Fix typo.

useful for fields like meta.maintainers, meta.priority (which can be
  a proper integer now) and even meta.license (if there are multiple
  licenses).

Makefile.am

@@ -1,29 +1,26 @@
 SUBDIRS = externals src scripts corepkgs doc misc tests
 EXTRA_DIST = substitute.mk nix.spec nix.spec.in bootstrap.sh \
-  svn-revision nix.conf.example NEWS
+  nix.conf.example NEWS version
 
 include ./substitute.mk
 
 nix.spec: nix.spec.in
 
-rpm: nix.spec dist
-	rpm $(EXTRA_RPM_FLAGS) -ta $(distdir).tar.gz
-
-relname:
-	echo -n $(distdir) > relname
-
 install-data-local: init-state
 	$(INSTALL) -d $(DESTDIR)$(sysconfdir)/nix
 	$(INSTALL_DATA) $(srcdir)/nix.conf.example $(DESTDIR)$(sysconfdir)/nix
 	if ! test -e $(DESTDIR)$(sysconfdir)/nix/nix.conf; then \
 		$(INSTALL_DATA) $(srcdir)/nix.conf.example $(DESTDIR)$(sysconfdir)/nix/nix.conf; \
 	fi
+	$(INSTALL) -d $(DESTDIR)$(docdir)
+	$(INSTALL_DATA) README $(DESTDIR)$(docdir)/
 
 if INIT_STATE
-if SETUID_HACK
-INIT_FLAGS = -g @NIX_GROUP@ -o @NIX_USER@
-GROUP_WRITABLE = -m 775
-endif
+
+# For setuid operation, you can enable the following:
+# INIT_FLAGS = -g @NIX_GROUP@ -o @NIX_USER@
+# GROUP_WRITABLE = -m 775
+
 init-state:
 	$(INSTALL) $(INIT_FLAGS) -d $(DESTDIR)$(localstatedir)/nix
 	$(INSTALL) $(INIT_FLAGS) -d $(DESTDIR)$(localstatedir)/nix/db
@@ -34,20 +31,18 @@ init-state:
 	$(INSTALL) $(INIT_FLAGS) -d $(DESTDIR)$(localstatedir)/nix/temproots
 	$(INSTALL) $(INIT_FLAGS) $(GROUP_WRITABLE) -d $(DESTDIR)$(localstatedir)/nix/gcroots/tmp
 	$(INSTALL) $(INIT_FLAGS) $(GROUP_WRITABLE) -d $(DESTDIR)$(localstatedir)/nix/gcroots/channels
-	rm -f $(DESTDIR)$(localstatedir)/nix/gcroots/profiles
-	ln -s $(localstatedir)/nix/profiles $(DESTDIR)$(localstatedir)/nix/gcroots/profiles
+	ln -sfn $(localstatedir)/nix/profiles $(DESTDIR)$(localstatedir)/nix/gcroots/profiles
 	$(INSTALL) $(INIT_FLAGS) -d $(DESTDIR)$(localstatedir)/nix/userpool
-	$(INSTALL) $(INIT_FLAGS) -m 1777 -d $(DESTDIR)$(prefix)/store
+	$(INSTALL) $(INIT_FLAGS) -m 1777 -d $(DESTDIR)$(storedir)
 	$(INSTALL) $(INIT_FLAGS) $(GROUP_WRITABLE) -d $(DESTDIR)$(localstatedir)/nix/manifests
-#	$(bindir)/nix-store --init
+	ln -sfn $(localstatedir)/nix/manifests $(DESTDIR)$(localstatedir)/nix/gcroots/manifests
+
 else
+
 init-state:
+
 endif
 
-svn-revision:
-	svnversion . > svn-revision
-
-all-local: NEWS
-
-NEWS: doc/manual/NEWS.txt
+NEWS:
+	$(MAKE) -C doc/manual NEWS.txt
 	cp $(srcdir)/doc/manual/NEWS.txt NEWS

README

@@ -1,9 +1,10 @@
-For installation and usage instructions, please read the manual, which
-can be found in `docs/manual/manual.html', and additionally at the Nix
-website at <http://www.cs.uu.nl/groups/ST/Trace/Nix>.
+Nix is a purely functional package manager.  For installation and
+usage instructions, please read the manual, which can be found in
+`docs/manual/manual.html', and additionally at the Nix website at
+<http://nixos.org/>.
 
 
 Acknowledgments
 
 This product includes software developed by the OpenSSL Project for
-use in the OpenSSL Toolkit (http://www.OpenSSL.org/)
+use in the OpenSSL Toolkit (http://www.OpenSSL.org/).

aterm-gc.supp

@@ -1,184 +1,117 @@
 {
    ATerm library conservatively scans for GC roots
    Memcheck:Cond
-   fun:mark_memory_young
-   fun:mark_phase_young
+   fun:*
+   fun:AT_collect_minor
 }
 
 {
    ATerm library conservatively scans for GC roots
    Memcheck:Cond
-   fun:AT_isValidSymbol
-   fun:mark_memory_young
-   fun:mark_phase_young
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:AT_isValidSymbol
-   fun:mark_memory_young
-   fun:mark_phase_young
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:mark_memory_young
-   fun:mark_phase_young
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:AT_isInsideValidTerm
-   fun:mark_memory_young
-   fun:mark_phase_young
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Cond
-   fun:AT_isInsideValidTerm
-   fun:mark_memory_young
-   fun:mark_phase_young
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:mark_memory_young
-   fun:mark_phase_young
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:AT_markTerm_young
-   fun:mark_memory_young
-   fun:mark_phase_young
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Cond
-   fun:AT_markTerm_young
-   fun:mark_memory_young
-   fun:mark_phase_young
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Cond
-   fun:mark_memory
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:mark_memory
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Cond
-   fun:AT_isValidSymbol
-   fun:mark_memory
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:AT_isValidSymbol
-   fun:mark_memory
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:AT_isInsideValidTerm
-   fun:mark_memory
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Cond
-   fun:AT_isInsideValidTerm
-   fun:mark_memory
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Cond
-   fun:AT_markTerm
-   fun:mark_memory
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:AT_markTerm
-   fun:mark_memory
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Value4
-   fun:AT_markTerm
-   fun:mark_memory
-   fun:mark_phase
-}
-
-{
-   ATerm library conservatively scans for GC roots
-   Memcheck:Cond
-   fun:mark_phase_young
+   fun:*
+   fun:*
    fun:AT_collect_minor
 }
 
 {
    ATerm library conservatively scans for GC roots
    Memcheck:Value4
-   fun:mark_phase_young
+   fun:*
    fun:AT_collect_minor
 }
 
 {
-   <insert a suppression name here>
-   Memcheck:Cond
-   fun:AT_isValidSymbol
-   fun:mark_phase_young
+   ATerm library conservatively scans for GC roots
+   Memcheck:Value8
+   fun:*
    fun:AT_collect_minor
 }
 
 {
-   <insert a suppression name here>
+   ATerm library conservatively scans for GC roots
    Memcheck:Value4
-   fun:AT_isValidSymbol
-   fun:mark_phase_young
+   fun:*
+   fun:*
    fun:AT_collect_minor
 }
 
 {
-   <insert a suppression name here>
-   Memcheck:Value4
-   fun:AT_isInsideValidTerm
-   fun:mark_phase_young
+   ATerm library conservatively scans for GC roots
+   Memcheck:Value8
+   fun:*
+   fun:*
    fun:AT_collect_minor
 }
 
 {
-   <insert a suppression name here>
+   ATerm library conservatively scans for GC roots
+   Memcheck:Addr4
+   fun:*
+   fun:AT_collect_minor
+}
+
+{
+   ATerm library conservatively scans for GC roots
+   Memcheck:Addr8
+   fun:*
+   fun:AT_collect_minor
+}
+
+{
+   ATerm library conservatively scans for GC roots
    Memcheck:Cond
-   fun:AT_isInsideValidTerm
-   fun:mark_phase_young
-   fun:AT_collect_minor
+   fun:*
+   fun:AT_collect
+}
+
+{
+   ATerm library conservatively scans for GC roots
+   Memcheck:Value4
+   fun:*
+   fun:AT_collect
+}
+
+{
+   ATerm library conservatively scans for GC roots
+   Memcheck:Value8
+   fun:*
+   fun:AT_collect
+}
+
+{
+   ATerm library conservatively scans for GC roots
+   Memcheck:Addr4
+   fun:*
+   fun:AT_collect
+}
+
+{
+   ATerm library conservatively scans for GC roots
+   Memcheck:Addr8
+   fun:*
+   fun:AT_collect
+}
+
+{
+   ATerm library conservatively scans for GC roots
+   Memcheck:Value4
+   fun:*
+   fun:*
+   fun:AT_collect
+}
+
+{
+   ATerm library conservatively scans for GC roots
+   Memcheck:Value8
+   fun:*
+   fun:*
+   fun:AT_collect
+}
+
+{
+   ATerm library conservatively scans for GC roots
+   Memcheck:Cond
+   fun:*
+   fun:*
+   fun:AT_collect
 }

configure.ac

@@ -1,24 +1,9 @@
-AC_INIT(nix, 0.10)
+AC_INIT(nix, m4_esyscmd([echo -n $(cat ./version)$VERSION_SUFFIX]))
 AC_CONFIG_SRCDIR(README)
 AC_CONFIG_AUX_DIR(config)
 AM_INIT_AUTOMAKE([dist-bzip2 foreign])
-        
-# Change to `1' to produce a `stable' release (i.e., the `preREVISION'
-# suffix is not added).
-STABLE=0
 
-# Put the revision number in the version.
-if test "$STABLE" != "1"; then
-    if REVISION=`test -d $srcdir/.svn && svnversion $srcdir 2> /dev/null`; then
-        VERSION=${VERSION}pre${REVISION}
-    elif REVISION=`cat $srcdir/svn-revision 2> /dev/null`; then
-        VERSION=${VERSION}pre${REVISION}
-    fi
-fi
-
-AC_DEFINE_UNQUOTED(NIX_VERSION, ["$(echo $VERSION)"], [version])
-
-AC_PREFIX_DEFAULT(/nix)
+AC_DEFINE_UNQUOTED(NIX_VERSION, ["$VERSION"], [Nix version.])
 
 AC_CANONICAL_HOST
 
@@ -32,6 +17,9 @@ case $machine_name in
     i*86)
         machine_name=i686
         ;;
+    x86_64)
+        machine_name=x86_64
+        ;;
     ppc)
         machine_name=powerpc
         ;;
@@ -51,21 +39,41 @@ case $sys_name in
 esac
 
 AC_ARG_WITH(system, AC_HELP_STRING([--with-system=SYSTEM],
-  [platform identifier (e.g., `i686-linux')]),
+  [Platform identifier (e.g., `i686-linux').]),
   system=$withval, system="${machine_name}-${sys_name}")
 AC_MSG_RESULT($system)
 AC_SUBST(system)
 AC_DEFINE_UNQUOTED(SYSTEM, ["$system"], [platform identifier (`cpu-os')])
 
 
+# State should be stored in /nix/var, unless the user overrides it explicitly.
+test "$localstatedir" = '${prefix}/var' && localstatedir=/nix/var
+
+
+# Whether to produce a statically linked binary.  On Cygwin, this is
+# the default: dynamically linking against the ATerm DLL does work,
+# except that it requires the ATerm "lib" directory to be in $PATH, as
+# Windows doesn't have anything like an RPATH embedded in executable.
+# Since this is kind of annoying, we use static libraries for now.
+    
+AC_ARG_ENABLE(static-nix, AC_HELP_STRING([--enable-static-nix],
+  [produce statically linked binaries]),
+  static_nix=$enableval, static_nix=no)
+
+if test "$sys_name" = cygwin; then
+   static_nix=yes
+fi
+  
+if test "$static_nix" = yes; then
+    AC_DISABLE_SHARED
+    AC_ENABLE_STATIC
+fi
+
+  
 # Windows-specific stuff.
 if test "$sys_name" = "cygwin"; then
     # We cannot delete open files.
     AC_DEFINE(CANNOT_DELETE_OPEN_FILES, 1, [Whether it is impossible to delete open files.])
-
-    # Shared libraries don't work, currently.
-    AC_DISABLE_SHARED
-    AC_ENABLE_STATIC
 fi
 
 
@@ -91,17 +99,34 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <iostream>
 using namespace std;
 static char buf[1024];]],
     [[cerr.rdbuf()->pubsetbuf(buf, sizeof(buf));]])],
-    [AC_MSG_RESULT(yes) AC_DEFINE(HAVE_PUBSETBUF, 1, [whether pubsetbuf is available])],
+    [AC_MSG_RESULT(yes) AC_DEFINE(HAVE_PUBSETBUF, 1, [Whether pubsetbuf is available.])],
     AC_MSG_RESULT(no))
 AC_LANG_POP(C++)
 
 
-# Check for <locale>
+# Check for chroot support (requires chroot() and bind mounts).
+AC_CHECK_FUNCS([chroot])
+AC_CHECK_FUNCS([unshare])
+AC_CHECK_HEADERS([sched.h], [], [], [])
+AC_CHECK_HEADERS([sys/param.h], [], [], [])
+AC_CHECK_HEADERS([sys/mount.h], [], [],
+[#ifdef HAVE_SYS_PARAM_H
+# include <sys/param.h>
+# endif
+])
+
+
+# Check for <locale>.
 AC_LANG_PUSH(C++)
-AC_CHECK_HEADERS([locale])
+AC_CHECK_HEADERS([locale], [], [], [])
 AC_LANG_POP(C++)
 
 
+# Check whether we have the personality() syscall, which allows us to
+# do i686-linux builds on x86_64-linux machines.
+AC_CHECK_HEADERS([sys/personality.h])
+
+
 AC_DEFUN([NEED_PROG],
 [
 AC_PATH_PROG($1, $2)
@@ -111,7 +136,7 @@ fi
 ])
 
 NEED_PROG(curl, curl)
-NEED_PROG(shell, sh)
+NEED_PROG(bash, bash)
 NEED_PROG(patch, patch)
 AC_PATH_PROG(xmllint, xmllint, false)
 AC_PATH_PROG(xsltproc, xsltproc, false)
@@ -122,8 +147,23 @@ AC_PATH_PROG(bison, bison, false)
 NEED_PROG(perl, perl)
 NEED_PROG(tar, tar)
 AC_PATH_PROG(dot, dot)
-                
+AC_PATH_PROG(dblatex, dblatex)
+AC_PATH_PROG(gzip, gzip)
+
+AC_PATH_PROG(openssl_prog, openssl, openssl) # if not found, call openssl in $PATH
+AC_SUBST(openssl_prog)
+AC_DEFINE_UNQUOTED(OPENSSL_PATH, ["$openssl_prog"], [Path of the OpenSSL binary])
+
+# Test that Perl has the open/fork feature (Perl 5.8.0 and beyond).
+AC_MSG_CHECKING([whether Perl is recent enough])
+if ! $perl -e 'open(FOO, "-|", "true"); while (<FOO>) { print; }; close FOO or die;'; then
+    AC_MSG_RESULT(no)
+    AC_MSG_ERROR([Your Perl version is too old.  Nix requires Perl 5.8.0 or newer.])
+fi
+AC_MSG_RESULT(yes)
+
 NEED_PROG(cat, cat)
+NEED_PROG(tr, tr)
 AC_ARG_WITH(coreutils-bin, AC_HELP_STRING([--with-coreutils-bin=PATH],
   [path of cat, mkdir, etc.]),
   coreutils=$withval, coreutils=$(dirname $cat))
@@ -146,11 +186,16 @@ AC_SUBST(xmlflags)
 
 AC_ARG_WITH(store-dir, AC_HELP_STRING([--with-store-dir=PATH],
   [path of the Nix store]),
-  storedir=$withval, storedir='${prefix}/store')
+  storedir=$withval, storedir='/nix/store')
 AC_SUBST(storedir)
 
+AC_ARG_ENABLE(old-db-compat, AC_HELP_STRING([--disable-old-db-compat],
+  [disable support for converting from old Berkeley DB-based Nix stores]),
+  old_db_compat=$enableval, old_db_compat=yes)
+AM_CONDITIONAL(OLD_DB_COMPAT, test "$old_db_compat" = "yes")
+
 AC_ARG_WITH(bdb, AC_HELP_STRING([--with-bdb=PATH],
-  [prefix of Berkeley DB]),
+  [prefix of Berkeley DB (for Nix <= 0.11 compatibility)]),
   bdb=$withval, bdb=)
 AM_CONDITIONAL(HAVE_BDB, test -n "$bdb")
 if test -z "$bdb"; then
@@ -160,6 +205,12 @@ else
   bdb_lib="-L$bdb/lib -ldb_cxx"
   bdb_include="-I$bdb/include"
 fi
+if test "$old_db_compat" = "no"; then
+  bdb_lib=
+  bdb_include=
+else
+  AC_DEFINE(OLD_DB_COMPAT, 1, [Whether to support converting from old Berkeley DB-based Nix stores.])
+fi
 AC_SUBST(bdb_lib)
 AC_SUBST(bdb_include)
 
@@ -188,7 +239,7 @@ if test -n "$openssl"; then
   LDFLAGS="-L$openssl/lib -lcrypto $LDFLAGS"
   CFLAGS="-I$openssl/include $CFLAGS"
   CXXFLAGS="-I$openssl/include $CXXFLAGS"
-  AC_DEFINE(HAVE_OPENSSL, 1, [whether to use OpenSSL])
+  AC_DEFINE(HAVE_OPENSSL, 1, [Whether to use OpenSSL.])
 fi
 
 AC_ARG_WITH(bzip2, AC_HELP_STRING([--with-bzip2=PATH],
@@ -201,7 +252,7 @@ if test -z "$bzip2"; then
   bzip2_lib='-L${top_builddir}/externals/inst-bzip2/lib -lbz2'
   bzip2_include='-I${top_builddir}/externals/inst-bzip2/include'
   # The binary will be copied to $libexecdir.
-  bzip2_bin='${libexecdir}'
+  bzip2_bin='${libexecdir}/nix'
   # But for testing, we have to use the temporary copy :-(
   bzip2_bin_test='${top_builddir}/externals/inst-bzip2/bin'
 else
@@ -226,33 +277,14 @@ AM_CONDITIONAL(INIT_STATE, test "$init_state" = "yes")
 
 
 # Setuid installations.
-AC_ARG_ENABLE(setuid, AC_HELP_STRING([--enable-setuid],
-  [install Nix setuid]),
-  setuid_hack=$enableval, setuid_hack=no)
-AM_CONDITIONAL(SETUID_HACK, test "$setuid_hack" = "yes")
-if test "$setuid_hack" = "yes"; then
-    AC_DEFINE(SETUID_HACK, 1, [whether to install Nix setuid])
-fi
+AC_CHECK_FUNCS([setresuid setreuid lchown])
 
-AC_CHECK_FUNC(setresuid, [HAVE_SETRESUID=1], [HAVE_SETRESUID=])
-AM_CONDITIONAL(HAVE_SETRESUID, test "$HAVE_SETRESUID" = "1")
-if test "$HAVE_SETRESUID" = "1"; then
-    AC_DEFINE(HAVE_SETRESUID, 1, [whether we have setresuid()])
-fi
 
-AC_ARG_WITH(nix-user, AC_HELP_STRING([--with-nix-user=USER],
-  [user for Nix setuid binaries]),
-  NIX_USER=$withval, NIX_USER=nix)
-AC_SUBST(NIX_USER)
-AC_DEFINE_UNQUOTED(NIX_USER, ["$NIX_USER"], [Nix user])
-                                                      
-AC_ARG_WITH(nix-group, AC_HELP_STRING([--with-nix-group=USER],
-  [group for Nix setuid binaries]),
-  NIX_GROUP=$withval, NIX_GROUP=nix)
-AC_SUBST(NIX_GROUP)
-AC_DEFINE_UNQUOTED(NIX_GROUP, ["$NIX_GROUP"], [Nix group])
+# Nice to have, but not essential.
+AC_CHECK_FUNCS([strsignal])
+AC_CHECK_FUNCS([posix_fallocate])
+
 
-                                                                                                            
 # This is needed if ATerm, Berkeley DB or bzip2 are static libraries,
 # and the Nix libraries are dynamic.
 if test "$(uname)" = "Darwin"; then
@@ -260,6 +292,14 @@ if test "$(uname)" = "Darwin"; then
 fi
 
 
+if test "$static_nix" = yes; then
+    # `-all-static' has to be added at the end of configure, because
+    # the C compiler doesn't know about -all-static (it's filtered out
+    # by libtool, but configure doesn't use libtool).
+    LDFLAGS="-all-static $LDFLAGS"
+fi
+
+
 AM_CONFIG_HEADER([config.h])
 AC_CONFIG_FILES([Makefile
    externals/Makefile
@@ -275,6 +315,8 @@ AC_CONFIG_FILES([Makefile
    src/libexpr/Makefile
    src/nix-instantiate/Makefile
    src/nix-env/Makefile
+   src/nix-worker/Makefile
+   src/nix-setuid-helper/Makefile
    src/nix-log2xml/Makefile
    src/bsdiff-4.3/Makefile
    scripts/Makefile

corepkgs/buildenv/builder.pl.in

@@ -12,13 +12,15 @@ mkdir "$out", 0755 || die "error creating $out";
 
 my $symlinks = 0;
 
+my %priorities;
+
 
 # For each activated package, create symlinks.
 
 sub createLinks {
     my $srcDir = shift;
     my $dstDir = shift;
-    my $ignoreCollisions = shift;
+    my $priority = shift;
 
     my @srcFiles = glob("$srcDir/*");
 
@@ -42,7 +44,7 @@ sub createLinks {
             lstat $dstFile;
             
             if (-d _) {
-                createLinks($srcFile, $dstFile, $ignoreCollisions);
+                createLinks($srcFile, $dstFile, $priority);
             }
 
             elsif (-l _) {
@@ -53,27 +55,35 @@ sub createLinks {
                 unlink $dstFile or die "error unlinking `$dstFile': $!";
                 mkdir $dstFile, 0755 || 
                     die "error creating directory `$dstFile': $!";
-                createLinks($target, $dstFile, $ignoreCollisions);
-                createLinks($srcFile, $dstFile, $ignoreCollisions);
+                createLinks($target, $dstFile, $priorities{$dstFile});
+                createLinks($srcFile, $dstFile, $priority);
             }
 
             else {
                 symlink($srcFile, $dstFile) ||
                     die "error creating link `$dstFile': $!";
+                $priorities{$dstFile} = $priority;
                 $symlinks++;
             }
         }
 
-        elsif (-l $dstFile) {
-            if (!$ignoreCollisions) {
-                my $target = readlink $dstFile;
-                die "collission between `$srcFile' and `$target'";
-            }
-        }
-
         else {
+
+            if (-l $dstFile) {
+                my $target = readlink $dstFile;
+                my $prevPriority = $priorities{$dstFile};
+                die ( "Collission between `$srcFile' and `$target'. "
+                    . "Suggested solution: use `nix-env --set-flag "
+                    . "priority NUMBER PKGNAME' to change the priority of "
+                    . "one of the conflicting packages.\n" )
+                    if $prevPriority == $priority;
+                next if $prevPriority < $priority;
+                unlink $dstFile or die;
+            }
+            
             symlink($srcFile, $dstFile) ||
                 die "error creating link `$dstFile': $!";
+            $priorities{$dstFile} = $priority;
             $symlinks++;
         }
     }
@@ -86,13 +96,13 @@ my %postponed;
 sub addPkg;
 sub addPkg {
     my $pkgDir = shift;
-    my $ignoreCollisions = shift;
+    my $priority = shift;
 
     return if (defined $done{$pkgDir});
     $done{$pkgDir} = 1;
 
 #    print "symlinking $pkgDir\n";
-    createLinks("$pkgDir", "$out", $ignoreCollisions);
+    createLinks("$pkgDir", "$out", $priority);
 
     my $propagatedFN = "$pkgDir/nix-support/propagated-user-env-packages";
     if (-e $propagatedFN) {
@@ -107,11 +117,29 @@ sub addPkg {
 }
 
 
-# Symlink to the packages that have been installed explicitly by the user.
-my @args = split ' ', $ENV{"derivations"};
+# Convert the stuff we get from the environment back into a coherent
+# data type.
+my @paths = split ' ', $ENV{"paths"};
+my @active = split ' ', $ENV{"active"};
+my @priority = split ' ', $ENV{"priority"};
 
-foreach my $pkgDir (sort @args) {
-    addPkg($pkgDir, 0);
+die if scalar @paths != scalar @active;
+die if scalar @paths != scalar @priority;
+
+my %pkgs;
+
+for (my $n = 0; $n < scalar @paths; $n++) {
+    $pkgs{$paths[$n]} =
+        { active => $active[$n]
+        , priority => $priority[$n] };
+}
+
+
+# Symlink to the packages that have been installed explicitly by the
+# user.
+foreach my $pkg (sort (keys %pkgs)) {
+    #print $pkg, " ", $pkgs{$pkg}->{priority}, "\n";
+    addPkg($pkg, $pkgs{$pkg}->{priority}) if $pkgs{$pkg}->{active} ne "false";
 }
 
 
@@ -119,11 +147,12 @@ foreach my $pkgDir (sort @args) {
 # installed by the user (i.e., package X declares that it want Y
 # installed as well).  We do these later because they have a lower
 # priority in case of collisions.
+my $priorityCounter = 1000; # don't care about collisions
 while (scalar(keys %postponed) > 0) {
     my @pkgDirs = keys %postponed;
     %postponed = ();
     foreach my $pkgDir (sort @pkgDirs) {
-        addPkg($pkgDir, 1);
+        addPkg($pkgDir, $priorityCounter++);
     }
 }
 

corepkgs/buildenv/default.nix

@@ -4,6 +4,11 @@ derivation {
   name = "user-environment";
   system = system;
   builder = ./builder.pl;
-  derivations = derivations;
+  
   manifest = manifest;
+
+  # !!! grmbl, need structured data for passing this in a clean way.
+  paths = derivations;
+  active = map (x: if x ? meta && x.meta ? active then x.meta.active else "true") derivations;
+  priority = map (x: if x ? meta && x.meta ? priority then x.meta.priority else "5") derivations;
 }

corepkgs/channels/unpack.sh.in

@@ -4,19 +4,29 @@
 @coreutils@/mkdir $out/tmp
 cd $out/tmp
 
-expr=$out/default.nix
-echo '[' > $expr
+inputs=($inputs)
+for ((n = 0; n < ${#inputs[*]}; n += 2)); do
+    channelName=${inputs[n]}
+    channelTarball=${inputs[n+1]}
+    
+    echo "unpacking channel $channelName"
+    
+    @bunzip2@ < $channelTarball | @tar@ xf -
 
-nr=0
-for i in $inputs; do
-    echo "unpacking $i"
-    @bunzip2@ < $i | @tar@ xf -
-    @coreutils@/mv * ../$nr # !!! hacky
-    echo "(import ./$nr)" >> $expr
-    nr=$(($nr + 1))
+    if test -e */channel-name; then
+        channelName="$(@coreutils@/cat */channel-name)"
+    fi
+
+    nr=1
+    attrName=$(echo $channelName | @tr@ -- '- ' '__')
+    dirName=$attrName
+    while test -e ../$dirName; do
+        nr=$((nr+1))
+        dirName=$attrName-$nr
+    done
+
+    @coreutils@/mv * ../$dirName # !!! hacky
 done
 
-echo ']' >> $expr
-
 cd ..
 @coreutils@/rmdir tmp

doc/dev/release-procedures.txt

@@ -1,5 +1,8 @@
 To produce a `stable' release from the trunk:
 
+-1. Update the release notes; make sure that the release date is
+    correct.
+
 0. Make sure that the trunk builds in the release supervisor.
 
 1. Branch the trunk, e.g., `svn cp .../trunk
@@ -22,8 +25,8 @@ To produce a `stable' release from the trunk:
    branch (e.g., `.../branches/0.5') should be created from the
    original revision of the trunk (since maintenance releases should
    also be tested first; hence, we cannot have `STABLE=1').  The same
-   procedure can then be followed to produce maintenance release; just
-   substitute `.../branches/VERSION' for the trunk.
+   procedure can then be followed to produce maintenance releases;
+   just substitute `.../branches/VERSION' for the trunk.
 
 7. Switch back to the trunk.
 

doc/manual/Makefile.am

@@ -14,15 +14,16 @@ XSLTPROC = $(xsltproc) $(xmlflags) \
 man1_MANS = nix-env.1 nix-build.1 nix-store.1 nix-instantiate.1 \
  nix-collect-garbage.1 nix-push.1 nix-pull.1 \
  nix-prefetch-url.1 nix-channel.1 \
- nix-pack-closure.1 nix-unpack-closure.1 \
- nix-install-package.1 nix-hash.1
+ nix-install-package.1 nix-hash.1 nix-copy-closure.1
+
+man8_MANS = nix-worker.8
 
 FIGURES = figures/user-environments.png
 
 MANUAL_SRCS = manual.xml introduction.xml installation.xml \
- package-management.xml writing-nix-expressions.xml \
+ package-management.xml writing-nix-expressions.xml builtins.xml \
  build-farm.xml \
- $(man1_MANS:.1=.xml) \
+ $(man1_MANS:.1=.xml) $(man8_MANS:.8=.xml) \
  troubleshooting.xml bugs.xml opt-common.xml opt-common-syn.xml \
  env-common.xml quick-start.xml nix-lang-ref.xml glossary.xml \
  conf-file.xml release-notes.xml \
@@ -31,7 +32,7 @@ MANUAL_SRCS = manual.xml introduction.xml installation.xml \
 manual.is-valid: $(MANUAL_SRCS) version.txt
 #	$(XMLLINT) --xinclude $< | $(XMLLINT) --noout --nonet --relaxng $(docbookrng)/docbook.rng -
 	if test "$(jing)" != "false"; then \
-		$(XMLLINT) --xinclude $< | $(jing) $(docbookrng)/docbook.rng /dev/stdin; \
+		$(XMLLINT) --xinclude $< | $(jing) $(docbookrng)/docbook.rng /dev/fd/0; \
 	else \
 		echo "Not validating."; \
 	fi
@@ -47,6 +48,14 @@ manual.html: $(MANUAL_SRCS) manual.is-valid images
 	$(XSLTPROC) --nonet --xinclude --output manual.html \
 	  $(docbookxsl)/html/docbook.xsl manual.xml
 
+manual.pdf: $(MANUAL_SRCS) manual.is-valid images
+	if test "$(dblatex)" != ""; then \
+		$(dblatex) manual.xml; \
+	else \
+		echo "Please install dblatex and rerun configure."; \
+		exit 1; \
+	fi
+
 
 NEWS_OPTS = \
  --stringparam generate.toc "article nop" \
@@ -68,12 +77,16 @@ NEWS.txt: release-notes.xml
 all-local: manual.html NEWS.html NEWS.txt
 
 install-data-local: manual.html
-	$(INSTALL) -d $(DESTDIR)$(datadir)/nix/manual
-	$(INSTALL_DATA) manual.html $(DESTDIR)$(datadir)/nix/manual
-	$(INSTALL_DATA) style.css $(DESTDIR)$(datadir)/nix/manual
-	cp -r images $(DESTDIR)$(datadir)/nix/manual/images
-	$(INSTALL) -d $(DESTDIR)$(datadir)/nix/manual/figures
-	$(INSTALL_DATA) $(FIGURES) $(DESTDIR)$(datadir)/nix/manual/figures
+	$(INSTALL) -d $(DESTDIR)$(docdir)/manual
+	$(INSTALL_DATA) manual.html $(DESTDIR)$(docdir)/manual
+	ln -sf manual.html $(DESTDIR)$(docdir)/manual/index.html
+	$(INSTALL_DATA) style.css $(DESTDIR)$(docdir)/manual
+	cp -r images $(DESTDIR)$(docdir)/manual/images
+	$(INSTALL) -d $(DESTDIR)$(docdir)/manual/figures
+	$(INSTALL_DATA) $(FIGURES) $(DESTDIR)$(docdir)/manual/figures
+	$(INSTALL) -d $(DESTDIR)$(docdir)/release-notes
+	$(INSTALL_DATA) NEWS.html $(DESTDIR)$(docdir)/release-notes/index.html
+	$(INSTALL_DATA) style.css $(DESTDIR)$(docdir)/release-notes/
 
 images:
 	mkdir images

doc/manual/bugs.xml

@@ -15,18 +15,6 @@ generation 43 is created which is a descendant of 39, not 42.  So a
 rollback from 43 ought to go back to 39.  This is not currently
 implemented; generations form a linear sequence.</para></listitem>
 
-<listitem><para><emphasis>Build management.</emphasis> In principle it
-is already possible to do build management using Nix (by writing
-builders that perform appropriate build steps), but the Nix expression
-language is not yet powerful enough to make this pleasant (?).  The
-language should be extended with features from the <link
-xlink:href='http://www.cs.uu.nl/~eelco/maak/'>Maak build
-manager</link>.  Another interesting idea is to write a
-<command>make</command> implementation that uses Nix as a back-end to
-support <link
-xlink:href='http://www.research.att.com/~bs/bs_faq.html#legacy'>legacy</link>
-build files.</para></listitem>
-
 <listitem><para>For security, <command>nix-push</command> manifests
 should be digitally signed, and <command>nix-pull</command> should
 verify the signatures.  The actual NAR archives in the cache do not

doc/manual/build-farm.xml

@@ -36,10 +36,10 @@ build farm, since:
   builds, and Nix expressions are self-contained.</para></listitem>
 
   <listitem><para>Nix will only rebuild things that have actually
-  changed.  For instance, if the sources of a component haven't
-  changed between runs of the build farm, the component won't be
-  rebuild (unless it was garbage-collected).  Also, dependencies
-  typically don't change very often, so they only need to be built
+  changed.  For instance, if the sources of a package haven't changed
+  between runs of the build farm, the package won't be rebuilt (unless
+  it was garbage-collected).  Also, dependencies typically don't
+  change very often, so they only need to be built
   once.</para></listitem>
 
   <listitem><para>The results of a Nix build farm can be made
@@ -56,7 +56,7 @@ build farm, since:
 <para>TODO</para>
 
 <para>The sources of the Nix build farm are at <link
-xlink:href='https://svn.cs.uu.nl:12443/repos/trace/release/trunk'/>.</para>
+xlink:href='https://svn.nixos.org/repos/nix/release/trunk'/>.</para>
 
 </section>
 
@@ -85,7 +85,7 @@ nix@scratchy.labs.cs.uu.nl  i686-linux      /home/nix/.ssh/id_scratchy_auto
 
 <para>An example build hook can be found in the Nix build farm
 sources: <link
-xlink:href='https://svn.cs.uu.nl:12443/repos/trace/release/trunk/common/distributed/build-remote.pl'
+xlink:href='https://svn.nixos.org/repos/nix/release/trunk/common/distributed/build-remote.pl'
 />.  It should be suitable for most purposes, with maybe some minor
 adjustments.  It uses <command>ssh</command> and
 <command>rsync</command> to copy the build inputs and outputs and

doc/manual/builtins.xml

@@ -0,0 +1,841 @@
+<section xmlns="http://docbook.org/ns/docbook"
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id='ssec-builtins'>
+
+<title>Built-in functions</title>
+
+
+<para>This section lists the functions and constants built into the
+Nix expression evaluator.  (The built-in function
+<function>derivation</function> is discussed above.)  Some built-ins,
+such as <function>derivation</function>, are always in scope of every
+Nix expression; you can just access them right away.  But to prevent
+polluting the namespace too much, most built-ins are not in scope.
+Instead, you can access them through the <varname>builtins</varname>
+built-in value, which is an attribute set that contains all built-in
+functions and values.  For instance, <function>derivation</function>
+is also available as <function>builtins.derivation</function>.</para>
+
+
+<variablelist>
+
+  
+  <varlistentry><term><function>abort</function> <replaceable>s</replaceable></term>
+
+    <listitem><para>Abort Nix expression evaluation, print error
+    message <replaceable>s</replaceable>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.add</function>
+  <replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
+
+    <listitem><para>Return the sum of the integers
+    <replaceable>e1</replaceable> and
+    <replaceable>e2</replaceable>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.attrNames</function>
+  <replaceable>attrs</replaceable></term>
+
+    <listitem><para>Return the names of the attributes in the
+    attribute set <replaceable>attrs</replaceable> in a sorted list.
+    For instance, <literal>builtins.attrNames {y = 1; x =
+    "foo";}</literal> evaluates to <literal>["x" "y"]</literal>.
+    There is no built-in function <function>attrValues</function>, but
+    you can easily define it yourself:
+
+<programlisting>
+attrValues = attrs: map (name: builtins.getAttr name attrs) (builtins.attrNames attrs);</programlisting>
+
+    </para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>baseNameOf</function> <replaceable>s</replaceable></term>
+
+    <listitem><para>Return the <emphasis>base name</emphasis> of the
+    string <replaceable>s</replaceable>, that is, everything following
+    the final slash in the string.  This is similar to the GNU
+    <command>basename</command> command.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><varname>builtins</varname></term>
+
+    <listitem><para>The attribute set <varname>builtins</varname>
+    contains all the built-in functions and values.  You can use
+    <varname>builtins</varname> to test for the availability of
+    features in the Nix installation, e.g.,
+
+<programlisting>
+if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting>
+
+    This allows a Nix expression to fall back gracefully on older Nix
+    installations that don’t have the desired built-in
+    function.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.compareVersions</function>
+  <replaceable>s1</replaceable> <replaceable>s2</replaceable></term>
+
+    <listitem><para>Compare two strings representing versions and
+    return <literal>-1</literal> if version
+    <replaceable>s1</replaceable> is older than version
+    <replaceable>s2</replaceable>, <literal>0</literal> if they are
+    the same, and <literal>1</literal> if
+    <replaceable>s1</replaceable> is newer than
+    <replaceable>s2</replaceable>.  The version comparison algorithm
+    is the same as the one used by <link
+    linkend="ssec-version-comparisons"><command>nix-env
+    -u</command></link>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry
+  xml:id='builtin-currentSystem'><term><varname>builtins.currentSystem</varname></term>
+
+    <listitem><para>The built-in value <varname>currentSystem</varname>
+    evaluates to the Nix platform identifier for the Nix installation
+    on which the expression is being evaluated, such as
+    <literal>"i686-linux"</literal> or
+    <literal>"powerpc-darwin"</literal>.</para></listitem>
+
+  </varlistentry>
+
+
+  <!--
+  <varlistentry><term><function>currentTime</function></term>
+
+    <listitem><para>The built-in value <varname>currentTime</varname>
+    returns the current system time in seconds since 00:00:00 1/1/1970
+    UTC.  Due to the evaluation model of Nix expressions
+    (<emphasis>maximal laziness</emphasis>), it always yields the same
+    value within an execution of Nix.</para></listitem>
+
+  </varlistentry>
+  -->
+
+  
+  <!--
+  <varlistentry><term><function>dependencyClosure</function></term>
+
+    <listitem><para>TODO</para></listitem>
+
+  </varlistentry>
+  -->
+
+  
+  <varlistentry><term><function>derivation</function>
+  <replaceable>attrs</replaceable></term>
+
+    <listitem><para><function>derivation</function> is described in
+    <xref linkend='ssec-derivation' />.</para></listitem>
+
+  </varlistentry>
+
+
+  <varlistentry><term><function>dirOf</function> <replaceable>s</replaceable></term>
+
+    <listitem><para>Return the directory part of the string
+    <replaceable>s</replaceable>, that is, everything before the final
+    slash in the string.  This is similar to the GNU
+    <command>dirname</command> command.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.div</function>
+  <replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
+
+    <listitem><para>Return the quotient of the integers
+    <replaceable>e1</replaceable> and
+    <replaceable>e2</replaceable>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.filterSource</function>
+  <replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
+
+    <listitem>
+
+      <para>This function allows you to copy sources into the Nix
+      store while filtering certain files.  For instance, suppose that
+      you want to use the directory <filename>source-dir</filename> as
+      an input to a Nix expression, e.g.
+
+<programlisting>
+stdenv.mkDerivation {
+  ...
+  src = ./source-dir;
+}
+</programlisting>
+
+      However, if <filename>source-dir</filename> is a Subversion
+      working copy, then all those annoying <filename>.svn</filename>
+      subdirectories will also be copied to the store.  Worse, the
+      contents of those directories may change a lot, causing lots of
+      spurious rebuilds.  With <function>filterSource</function> you
+      can filter out the <filename>.svn</filename> directories:
+
+<programlisting>
+  src = builtins.filterSource
+    (path: type: type != "directory" || baseNameOf path != ".svn")
+    ./source-dir;
+</programlisting>
+
+      </para>
+
+      <para>Thus, the first argument <replaceable>e1</replaceable>
+      must be a predicate function that is called for each regular
+      file, directory or symlink in the source tree
+      <replaceable>e2</replaceable>.  If the function returns
+      <literal>true</literal>, the file is copied to the Nix store,
+      otherwise it is omitted.  The function is called with two
+      arguments.  The first is the full path of the file.  The second
+      is a string that identifies the type of the file, which is
+      either <literal>"regular"</literal>,
+      <literal>"directory"</literal>, <literal>"symlink"</literal> or
+      <literal>"unknown"</literal> (for other kinds of files such as
+      device nodes or fifos — but note that those cannot be copied to
+      the Nix store, so if the predicate returns
+      <literal>true</literal> for them, the copy will fail).</para>
+
+    </listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.getAttr</function>
+  <replaceable>s</replaceable> <replaceable>attrs</replaceable></term>
+
+    <listitem><para><function>getAttr</function> returns the attribute
+    named <replaceable>s</replaceable> from the attribute set
+    <replaceable>attrs</replaceable>.  Evaluation aborts if the
+    attribute doesn’t exist.  This is a dynamic version of the
+    <literal>.</literal> operator, since <replaceable>s</replaceable>
+    is an expression rather than an identifier.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.getEnv</function>
+  <replaceable>s</replaceable></term>
+
+    <listitem><para><function>getEnv</function> returns the value of
+    the environment variable <replaceable>s</replaceable>, or an empty
+    string if the variable doesn’t exist.  This function should be
+    used with care, as it can introduce all sorts of nasty environment
+    dependencies in your Nix expression.</para>
+
+    <para><function>getEnv</function> is used in Nix Packages to
+    locate the file <filename>~/.nixpkgs/config.nix</filename>, which
+    contains user-local settings for Nix Packages.  (That is, it does
+    a <literal>getEnv "HOME"</literal> to locate the user’s home
+    directory.)</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.hasAttr</function>
+  <replaceable>s</replaceable> <replaceable>attrs</replaceable></term>
+
+    <listitem><para><function>hasAttr</function> returns
+    <literal>true</literal> if the attribute set
+    <replaceable>attrs</replaceable> has an attribute named
+    <replaceable>s</replaceable>, and <literal>false</literal>
+    otherwise.  This is a dynamic version of the <literal>?</literal>
+    operator, since <replaceable>s</replaceable> is an expression
+    rather than an identifier.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.head</function>
+  <replaceable>list</replaceable></term>
+
+    <listitem><para>Return the first element of a list; abort
+    evaluation if the argument isn’t a list or is an empty list.  You
+    can test whether a list is empty by comparing it with
+    <literal>[]</literal>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>import</function>
+  <replaceable>path</replaceable></term>
+
+    <listitem><para>Load, parse and return the Nix expression in the
+    file <replaceable>path</replaceable>.  Evaluation aborts if the
+    file doesn’t exist or contains an incorrect Nix
+    expression.  <function>import</function> implements Nix’s module
+    system: you can put any Nix expression (such as an attribute set
+    or a function) in a separate file, and use it from Nix expressions
+    in other files.</para>
+
+    <para>A Nix expression loaded by <function>import</function> must
+    not contain any <emphasis>free variables</emphasis> (identifiers
+    that are not defined in the Nix expression itself and are not
+    built-in).  Therefore, it cannot refer to variables that are in
+    scope at the call site.  For instance, if you have a calling
+    expression
+    
+<programlisting>
+rec {
+  x = 123;
+  y = import ./foo.nix;
+}</programlisting>
+
+    then the following <filename>foo.nix</filename> will give an
+    error:
+
+<programlisting>
+x + 456</programlisting>
+
+    since <varname>x</varname> is not in scope in
+    <filename>foo.nix</filename>.  If you want <varname>x</varname>
+    to be available in <filename>foo.nix</filename>, you should pass
+    it as a function argument:
+
+<programlisting>
+rec {
+  x = 123;
+  y = import ./foo.nix x;
+}</programlisting>
+
+    and
+
+<programlisting>
+x: x + 456</programlisting>
+
+    (The function argument doesn’t have to be called
+    <varname>x</varname> in <filename>foo.nix</filename>; any name
+    would work.)</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.isAttrs</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Return <literal>true</literal> if
+    <replaceable>e</replaceable> evaluates to an attribute set, and
+    <literal>false</literal> otherwise.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.isList</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Return <literal>true</literal> if
+    <replaceable>e</replaceable> evaluates to a list, and
+    <literal>false</literal> otherwise.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.isFunction</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Return <literal>true</literal> if
+    <replaceable>e</replaceable> evaluates to a function, and
+    <literal>false</literal> otherwise.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.isString</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Return <literal>true</literal> if
+    <replaceable>e</replaceable> evaluates to a string, and
+    <literal>false</literal> otherwise.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.isInt</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Return <literal>true</literal> if
+    <replaceable>e</replaceable> evaluates to a int, and
+    <literal>false</literal> otherwise.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.isBool</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Return <literal>true</literal> if
+    <replaceable>e</replaceable> evaluates to a bool, and
+    <literal>false</literal> otherwise.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>isNull</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Return <literal>true</literal> if
+    <replaceable>e</replaceable> evaluates to <literal>null</literal>,
+    and <literal>false</literal> otherwise.</para>
+
+    <warning><para>This function is <emphasis>deprecated</emphasis>;
+    just write <literal>e == null</literal> instead.</para></warning>
+    
+    </listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.length</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Return the length of the list
+    <replaceable>e</replaceable>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.lessThan</function>
+  <replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
+
+    <listitem><para>Return <literal>true</literal> if the integer
+    <replaceable>e1</replaceable> is less than the integer
+    <replaceable>e2</replaceable>, and <literal>false</literal>
+    otherwise.  Evaluation aborts if either
+    <replaceable>e1</replaceable> or <replaceable>e2</replaceable>
+    does not evaluate to an integer.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.listToAttrs</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Construct an attribute set from a list specifying
+    the names and values of each attribute.  Each element of the list
+    should be an attribute set consisting of a string-valued attribute
+    <varname>name</varname> specifying the name of the attribute, and
+    an attribute <varname>value</varname> specifying its value.
+    Example:
+
+<programlisting>
+builtins.listToAttrs [
+  {name = "foo"; value = 123;}
+  {name = "bar"; value = 456;}
+]
+</programlisting>
+
+    evaluates to
+
+<programlisting>
+{ foo = 123; bar = 456; }
+</programlisting>
+
+    </para></listitem>
+
+  </varlistentry>
+  
+  <varlistentry><term><function>map</function>
+  <replaceable>f</replaceable> <replaceable>list</replaceable></term>
+
+    <listitem><para>Apply the function <replaceable>f</replaceable> to
+    each element in the list <replaceable>list</replaceable>.  For
+    example,
+
+<programlisting>
+map (x: "foo" + x) ["bar" "bla" "abc"]</programlisting>
+
+    evaluates to <literal>["foobar" "foobla"
+    "fooabc"]</literal>.</para></listitem>
+    
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.mul</function>
+  <replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
+
+    <listitem><para>Return the product of the integers
+    <replaceable>e1</replaceable> and
+    <replaceable>e2</replaceable>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.parseDrvName</function>
+  <replaceable>s</replaceable></term>
+
+    <listitem><para>Split the string <replaceable>s</replaceable> into
+    a package name and version.  The package name is everything up to
+    but not including the first dash followed by a digit, and the
+    version is everything following that dash.  The result is returned
+    in an attribute set <literal>{name, version}</literal>.  Thus,
+    <literal>builtins.parseDrvName "nix-0.12pre12876"</literal>
+    returns <literal>{name = "nix"; version =
+    "0.12pre12876";}</literal>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.pathExists</function>
+  <replaceable>path</replaceable></term>
+
+    <listitem><para>Return <literal>true</literal> if the path
+    <replaceable>path</replaceable> exists, and
+    <literal>false</literal> otherwise.  One application of this
+    function is to conditionally include a Nix expression containing
+    user configuration:
+
+<programlisting>
+let
+  fileName = builtins.getEnv "CONFIG_FILE";
+  config =
+    if fileName != "" &amp;&amp; builtins.pathExists (builtins.toPath fileName)
+    then import (builtins.toPath fileName)
+    else { someSetting = false; }; <lineannotation># default configuration</lineannotation>
+in config.someSetting</programlisting>
+
+    (Note that <envar>CONFIG_FILE</envar> must be an absolute path for
+    this to work.)</para></listitem>
+
+  </varlistentry>
+
+
+  <!--
+  <varlistentry><term><function>relativise</function></term>
+
+    <listitem><para>TODO</para></listitem>
+
+  </varlistentry>
+  -->
+
+  
+  <varlistentry><term><function>builtins.readFile</function>
+  <replaceable>path</replaceable></term>
+
+    <listitem><para>Return the contents of the file
+    <replaceable>path</replaceable> as a string.</para></listitem>
+
+  </varlistentry>
+  
+  
+  <varlistentry><term><function>removeAttrs</function>
+  <replaceable>attrs</replaceable> <replaceable>list</replaceable></term>
+
+    <listitem><para>Remove the attributes listed in
+    <replaceable>list</replaceable> from the attribute set
+    <replaceable>attrs</replaceable>.  The attributes don’t have to
+    exist in <replaceable>attrs</replaceable>. For instance,
+
+<screen>
+removeAttrs { x = 1; y = 2; z = 3; } ["a" "x" "z"]</screen>
+
+    evaluates to <literal>{y = 2;}</literal>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.stringLength</function>
+  <replaceable>e</replaceable></term>
+
+    <listitem><para>Return the length of the string
+    <replaceable>e</replaceable>.  If <replaceable>e</replaceable> is
+    not a string, evaluation is aborted.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.sub</function>
+  <replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
+
+    <listitem><para>Return the difference between the integers
+    <replaceable>e1</replaceable> and
+    <replaceable>e2</replaceable>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.substring</function>
+  <replaceable>start</replaceable> <replaceable>len</replaceable>
+  <replaceable>s</replaceable></term>
+
+    <listitem><para>Return the substring of
+    <replaceable>s</replaceable> from character position
+    <replaceable>start</replaceable> (zero-based) up to but not
+    including <replaceable>start + len</replaceable>.  If
+    <replaceable>start</replaceable> is greater than the length of the
+    string, an empty string is returned, and if <replaceable>start +
+    len</replaceable> lies beyond the end of the string, only the
+    substring up to the end of the string is returned.
+    <replaceable>start</replaceable> must be
+    non-negative.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.tail</function>
+  <replaceable>list</replaceable></term>
+
+    <listitem><para>Return the second to last elements of a list;
+    abort evaluation if the argument isn’t a list or is an empty
+    list.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>throw</function>
+  <replaceable>s</replaceable></term>
+
+    <listitem><para>Throw an error message
+    <replaceable>s</replaceable>.  This usually aborts Nix expression
+    evaluation, but in <command>nix-env -qa</command> and other
+    commands that try to evaluate a set of derivations to get
+    information about those derivations, a derivation that throws an
+    error is silently skipped (which is not the case for
+    <function>abort</function>).</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry
+  xml:id='builtin-toFile'><term><function>builtins.toFile</function>
+  <replaceable>name</replaceable> <replaceable>s</replaceable></term>
+
+    <listitem><para>Store the string <replaceable>s</replaceable> in a
+    file in the Nix store and return its path.  The file has suffix
+    <replaceable>name</replaceable>.  This file can be used as an
+    input to derivations.  One application is to write builders
+    “inline”.  For instance, the following Nix expression combines
+    <xref linkend='ex-hello-nix' /> and <xref
+    linkend='ex-hello-builder' /> into one file:
+
+<programlisting>
+{stdenv, fetchurl, perl}:
+
+stdenv.mkDerivation {
+  name = "hello-2.1.1";
+  
+  builder = builtins.toFile "builder.sh" "
+    source $stdenv/setup
+
+    PATH=$perl/bin:$PATH
+
+    tar xvfz $src
+    cd hello-*
+    ./configure --prefix=$out
+    make
+    make install
+  ";
+
+  src = fetchurl {
+    url = http://nix.cs.uu.nl/dist/tarballs/hello-2.1.1.tar.gz;
+    md5 = "70c9ccf9fac07f762c24f2df2290784d";
+  };
+  inherit perl;
+}</programlisting>
+  
+    </para>
+
+    <para>It is even possible for one file to refer to another, e.g.,
+
+<programlisting>
+  builder = let
+    configFile = builtins.toFile "foo.conf" "
+      # This is some dummy configuration file.
+      <replaceable>...</replaceable>
+    ";
+  in builtins.toFile "builder.sh" "
+    source $stdenv/setup
+    <replaceable>...</replaceable>
+    cp ${configFile} $out/etc/foo.conf
+  ";</programlisting>
+
+    Note that <literal>${configFile}</literal> is an antiquotation
+    (see <xref linkend='ssec-values' />), so the result of the
+    expression <literal>configFile</literal> (i.e., a path like
+    <filename>/nix/store/m7p7jfny445k...-foo.conf</filename>) will be
+    spliced into the resulting string.</para>
+
+    <para>It is however <emphasis>not</emphasis> allowed to have files
+    mutually referring to each other, like so:
+
+<programlisting>
+let
+  foo = builtins.toFile "foo" "...${bar}...";
+  bar = builtins.toFile "bar" "...${foo}...";
+in foo</programlisting>
+
+    This is not allowed because it would cause a cyclic dependency in
+    the computation of the cryptographic hashes for
+    <varname>foo</varname> and <varname>bar</varname>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.toPath</function> <replaceable>s</replaceable></term>
+
+    <listitem><para>Convert the string value
+    <replaceable>s</replaceable> into a path value.  The string
+    <replaceable>s</replaceable> must represent an absolute path
+    (i.e., must start with <literal>/</literal>).  The path need not
+    exist.  The resulting path is canonicalised, e.g.,
+    <literal>builtins.toPath "//foo/xyzzy/../bar/"</literal> returns
+    <literal>/foo/bar</literal>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>toString</function> <replaceable>e</replaceable></term>
+
+    <listitem><para>Convert the expression
+    <replaceable>e</replaceable> to a string.
+    <replaceable>e</replaceable> can be a string (in which case
+    <function>toString</function> is a no-op) or a path (e.g.,
+    <literal>toString /foo/bar</literal> yields
+    <literal>"/foo/bar"</literal>.</para></listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry xml:id='builtin-toXML'><term><function>builtins.toXML</function> <replaceable>e</replaceable></term>
+
+    <listitem><para>Return a string containing an XML representation
+    of <replaceable>e</replaceable>.  The main application for
+    <function>toXML</function> is to communicate information with the
+    builder in a more structured format than plain environment
+    variables.</para>
+
+    <!-- TODO: more formally describe the schema of the XML
+    representation -->
+
+    <para><xref linkend='ex-toxml' /> shows an example where this is
+    the case.  The builder is supposed to generate the configuration
+    file for a <link xlink:href='http://jetty.mortbay.org/'>Jetty
+    servlet container</link>.  A servlet container contains a number
+    of servlets (<filename>*.war</filename> files) each exported under
+    a specific URI prefix.  So the servlet configuration is a list of
+    attribute sets containing the <varname>path</varname> and
+    <varname>war</varname> of the servlet (<xref
+    linkend='ex-toxml-co-servlets' />).  This kind of information is
+    difficult to communicate with the normal method of passing
+    information through an environment variable, which just
+    concatenates everything together into a string (which might just
+    work in this case, but wouldn’t work if fields are optional or
+    contain lists themselves).  Instead the Nix expression is
+    converted to an XML representation with
+    <function>toXML</function>, which is unambiguous and can easily be
+    processed with the appropriate tools.  For instance, in the
+    example an XSLT stylesheet (<xref linkend='ex-toxml-co-stylesheet'
+    />) is applied to it (<xref linkend='ex-toxml-co-apply' />) to
+    generate the XML configuration file for the Jetty server.  The XML
+    representation produced from <xref linkend='ex-toxml-co-servlets'
+    /> by <function>toXML</function> is shown in <xref
+    linkend='ex-toxml-result' />.</para>
+
+    <para>Note that <xref linkend='ex-toxml' /> uses the <function
+    linkend='builtin-toFile'>toFile</function> built-in to write the
+    builder and the stylesheet “inline” in the Nix expression.  The
+    path of the stylesheet is spliced into the builder at
+    <literal>xsltproc ${stylesheet}
+    <replaceable>...</replaceable></literal>.</para>
+
+    <example xml:id='ex-toxml'><title>Passing information to a builder
+    using <function>toXML</function></title>
+    
+<programlisting><![CDATA[
+{stdenv, fetchurl, libxslt, jira, uberwiki}:
+
+stdenv.mkDerivation (rec {
+  name = "web-server";
+
+  buildInputs = [libxslt];
+  
+  builder = builtins.toFile "builder.sh" "
+    source $stdenv/setup
+    mkdir $out
+    echo $servlets | xsltproc ${stylesheet} - > $out/server-conf.xml]]> <co xml:id='ex-toxml-co-apply' /> <![CDATA[
+  ";
+
+  stylesheet = builtins.toFile "stylesheet.xsl"]]> <co xml:id='ex-toxml-co-stylesheet' /> <![CDATA[
+   "<?xml version='1.0' encoding='UTF-8'?>
+    <xsl:stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform' version='1.0'>
+      <xsl:template match='/'>
+        <Configure>
+          <xsl:for-each select='/expr/list/attrs'>
+            <Call name='addWebApplication'>
+              <Arg><xsl:value-of select=\"attr[@name = 'path']/string/@value\" /></Arg>
+              <Arg><xsl:value-of select=\"attr[@name = 'war']/path/@value\" /></Arg>
+            </Call>
+          </xsl:for-each>
+        </Configure>
+      </xsl:template>
+    </xsl:stylesheet>
+  ";
+
+  servlets = builtins.toXML []]> <co xml:id='ex-toxml-co-servlets' /> <![CDATA[
+    { path = "/bugtracker"; war = jira + "/lib/atlassian-jira.war"; }
+    { path = "/wiki"; war = uberwiki + "/uberwiki.war"; }
+  ];
+})]]></programlisting>
+
+    </example>
+
+    <example xml:id='ex-toxml-result'><title>XML representation produced by
+    <function>toXML</function></title>
+    
+<programlisting><![CDATA[<?xml version='1.0' encoding='utf-8'?>
+<expr>
+  <list>
+    <attrs>
+      <attr name="path">
+        <string value="/bugtracker" />
+      </attr>
+      <attr name="war">
+        <path value="/nix/store/d1jh9pasa7k2...-jira/lib/atlassian-jira.war" />
+      </attr>
+    </attrs>
+    <attrs>
+      <attr name="path">
+        <string value="/wiki" />
+      </attr>
+      <attr name="war">
+        <path value="/nix/store/y6423b1yi4sx...-uberwiki/uberwiki.war" />
+      </attr>
+    </attrs>
+  </list>
+</expr>]]></programlisting>
+
+    </example>
+
+    </listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry><term><function>builtins.trace</function>
+  <replaceable>e1</replaceable> <replaceable>e2</replaceable></term>
+
+    <listitem><para>Evaluate <replaceable>e1</replaceable> and print its
+    abstract syntax representation on standard error.  Then return
+    <replaceable>e2</replaceable>.  This function is useful for
+    debugging.</para></listitem>
+
+  </varlistentry>
+
+  
+</variablelist>
+
+
+</section>

doc/manual/conf-file.xml

@@ -60,27 +60,6 @@ env-keep-derivations = false
   </varlistentry>
 
   
-  <varlistentry xml:id="conf-gc-reserved-space"><term><literal>gc-reserved-space</literal></term>
-
-    <listitem><para>This option specifies how much space should be
-    reserved in normal use so that the garbage collector can run
-    succesfully.  Since the garbage collector must perform Berkeley DB
-    transactions, it needs some disk space for itself.  However, when
-    the disk is full, this space is not available, so the collector
-    would not be able to run precisely when it is most needed.</para>
-
-    <para>For this reason, when Nix is run, it allocates a file
-    <filename>/nix/var/nix/db/reserved</filename> of the size
-    specified by this option.  When the garbage collector is run, this
-    file is deleted before the Berkeley DB environment is opened.
-    This should give it enough room to proceed.</para>
-
-    <para>The default is <literal>1048576</literal> (1
-    MiB).</para></listitem>
-
-  </varlistentry>
-
-  
   <varlistentry><term><literal>env-keep-derivations</literal></term>
 
     <listitem><para>If <literal>false</literal> (default), derivations
@@ -118,6 +97,123 @@ env-keep-derivations = false
   </varlistentry>
 
 
+  <varlistentry xml:id="conf-build-max-silent-time"><term><literal>build-max-silent-time</literal></term>
+
+    <listitem>
+
+      <para>This option defines the maximum number of seconds that a
+      builder can go without producing any data on standard output or
+      standard error.  This is useful (for instance in a automated
+      build system) to catch builds that are stuck in an infinite
+      loop, or to catch remote builds that are hanging due to network
+      problems.  It can be overriden using the <option
+      linkend="opt-max-silent-time">--max-silent-time</option> command
+      line switch.</para>
+
+      <para>The value <literal>0</literal> means that there is no
+      timeout.  This is also the default.</para>
+
+    </listitem>
+
+  </varlistentry>
+
+
+  <varlistentry xml:id="conf-build-users-group"><term><literal>build-users-group</literal></term>
+
+    <listitem><para>This options specifies the Unix group containing
+    the Nix build user accounts.  In multi-user Nix installations,
+    builds should not be performed by the Nix account since that would
+    allow users to arbitrarily modify the Nix store and database by
+    supplying specially crafted builders; and they cannot be performed
+    by the calling user since that would allow him/her to influence
+    the build result.</para>
+
+    <para>Therefore, if this option is non-empty and specifies a valid
+    group, builds will be performed under the user accounts that are a
+    member of the group specified here (as listed in
+    <filename>/etc/group</filename>).  Those user accounts should not
+    be used for any other purpose!</para>
+
+    <para>Nix will never run two builds under the same user account at
+    the same time.  This is to prevent an obvious security hole: a
+    malicious user writing a Nix expression that modifies the build
+    result of a legitimate Nix expression being built by another user.
+    Therefore it is good to have as many Nix build user accounts as
+    you can spare.  (Remember: uids are cheap.)</para>
+
+    <para>The build users should have permission to create files in
+    the Nix store, but not delete them.  Therefore,
+    <filename>/nix/store</filename> should be owned by the Nix
+    account, its group should be the group specified here, and its
+    mode should be <literal>1775</literal>.</para>
+
+    <para>If the build users group is empty, builds will be performed
+    under the uid of the Nix process (that is, the uid of the caller
+    if <envar>NIX_REMOTE</envar> is empty, the uid under which the Nix
+    daemon runs if <envar>NIX_REMOTE</envar> is
+    <literal>daemon</literal>, or the uid that owns the setuid
+    <command>nix-worker</command> program if <envar>NIX_REMOTE</envar>
+    is <literal>slave</literal>).  Obviously, this should not be used
+    in multi-user settings with untrusted users.</para>
+
+    </listitem>
+
+  </varlistentry>
+
+
+  <varlistentry><term><literal>build-use-chroot</literal></term>
+
+    <listitem><para>If set to <literal>true</literal>, builds will be
+    performed in a <emphasis>chroot environment</emphasis>, i.e., the
+    build will be isolated from the normal file system hierarchy and
+    will only see the Nix store, the temporary build directory, and
+    the directories configured with the <link
+    linkend='conf-build-chroot-dirs'><literal>build-chroot-dirs</literal>
+    option</link> (such as <filename>/proc</filename> and
+    <filename>/dev</filename>).  This is useful to prevent undeclared
+    dependencies on files in directories such as
+    <filename>/usr/bin</filename>.</para>
+
+    <para>The use of a chroot requires that Nix is run as root (but
+    you can still use the <link
+    linkend='conf-build-users-group'>“build users” feature</link> to
+    perform builds under different users than root).  Currently,
+    chroot builds only work on Linux because Nix uses “bind mounts” to
+    make the Nix store and other directories available inside the
+    chroot.</para>
+
+    </listitem>
+
+  </varlistentry>
+
+  
+  <varlistentry xml:id="conf-build-chroot-dirs"><term><literal>build-chroot-dirs</literal></term>
+
+    <listitem><para>When builds are performed in a chroot environment,
+    Nix will mount (using <command>mount --bind</command> on Linux)
+    some directories from the normal file system hierarchy inside the
+    chroot.  These are the Nix store, the temporary build directory
+    (usually
+    <filename>/tmp/nix-<replaceable>pid</replaceable>-<replaceable>number</replaceable></filename>)
+    and the directories listed here.  The default is <literal>dev
+    /proc</literal>.  Files in <filename>/dev</filename> (such as
+    <filename>/dev/null</filename>) are needed by many builds, and
+    some files in <filename>/proc</filename> may also be needed
+    occasionally.</para>
+
+    <para>The value used on NixOS is
+    
+<programlisting>
+build-use-chroot = /dev /proc /bin</programlisting>
+
+    to make the <filename>/bin/sh</filename> symlink available (which
+    is still needed by many builders).</para>
+
+    </listitem>
+
+  </varlistentry>
+
+  
   <varlistentry><term><literal>system</literal></term>
 
     <listitem><para>This option specifies the canonical Nix system

doc/manual/env-common.xml

@@ -10,17 +10,6 @@
 <variablelist>
 
   
-<varlistentry><term><envar>NIX_ROOT</envar></term>
-
-  <listitem><para>If <envar>NIX_ROOT</envar> is set, the Nix command
-  will on startup perform a <function>chroot()</function> to the
-  specified directory.  This is useful in certain bootstrapping
-  situations (e.g., when installing a Nix installation onto a hard
-  disk from CD-ROM).</para></listitem>
-
-</varlistentry>
-
-  
 <varlistentry><term><envar>NIX_IGNORE_SYMLINK_STORE</envar></term>
 
   <listitem>
@@ -162,12 +151,12 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
   <para>On the basis of this information, and whatever persistent
   state the build hook keeps about other machines and their current
   load, it has to decide what to do with the build.  It should print
-  out on file descriptor 3 one of the following responses (terminated
-  by a newline, <literal>"\n"</literal>):
+  out on standard error one of the following responses (terminated by
+  a newline, <literal>"\n"</literal>):
 
   <variablelist>
 
-    <varlistentry><term><literal>decline</literal></term>
+    <varlistentry><term><literal># decline</literal></term>
 
       <listitem><para>The build hook is not willing or able to perform
       the build; the calling Nix process should do the build itself,
@@ -175,7 +164,7 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 
     </varlistentry>
 
-    <varlistentry><term><literal>postpone</literal></term>
+    <varlistentry><term><literal># postpone</literal></term>
 
       <listitem><para>The build hook cannot perform the build now, but
       can do so in the future (e.g., because all available build slots
@@ -185,7 +174,7 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 
     </varlistentry>
 
-    <varlistentry><term><literal>accept</literal></term>
+    <varlistentry><term><literal># accept</literal></term>
 
       <listitem><para>The build hook has accepted the
       build.</para></listitem>
@@ -196,37 +185,12 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 
   </para>
 
-  <para>If the build hook accepts the build, it is possible that it is
-  no longer necessary to do the build because some other process has
-  performed the build in the meantime.  To prevent races, the hook
-  must read from file descriptor 4 a single line that tells it whether
-  to continue:
-
-  <variablelist>
-
-    <varlistentry><term><literal>cancel</literal></term>
-
-      <listitem><para>The build has already been done, so the hook
-      should exit.</para></listitem>
-
-    </varlistentry>
-  
-    <varlistentry><term><literal>okay</literal></term>
-
-      <listitem><para>The hook should proceed with the build.  At this
-      point, the calling Nix process has acquired locks on the output
-      path, so no other Nix process will perform the
-      build.</para></listitem>
-
-    </varlistentry>
-
-  </variablelist>
-
-  </para>
-
-  <para>If the hook has been told to proceed, Nix will store in the
-  hook’s current directory a number of text files that contain
-  information about the derivation:
+  <para>After sending <literal># accept</literal>, the hook should
+  read one line from standard input, which will be the string
+  <literal>okay</literal>.  It can then proceed with the build.
+  Before sending <literal>okay</literal>, Nix will store in the hook’s
+  current directory a number of text files that contain information
+  about the derivation:
 
   <variablelist>
 
@@ -266,7 +230,9 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
   <para>The hook should copy the inputs to the remote machine,
   register the validity of the inputs, perform the remote build, and
   copy the outputs back to the local machine.  An exit code other than
-  <literal>0</literal> indicates that the hook has failed.</para>
+  <literal>0</literal> indicates that the hook has failed.  An exit
+  code equal to 100 means that the remote build failed (as opposed to,
+  e.g., a network error).</para>
 
   </listitem>
 
@@ -274,6 +240,38 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 </varlistentry>
 
 
+<varlistentry xml:id="envar-remote"><term><envar>NIX_REMOTE</envar></term>
+
+  <listitem><para>This variable should be set to
+  <literal>daemon</literal> if you want to use the Nix daemon to
+  executed Nix operations, which is necessary in <link
+  linkend="ssec-multi-user">multi-user Nix installations</link>.
+  Otherwise, it should be left unset.</para></listitem>
+
+</varlistentry>
+
+    
+<varlistentry xml:id="envar-other-stores"><term><envar>NIX_OTHER_STORES</envar></term>
+
+  <listitem><para>This variable contains the paths of remote Nix
+  installations from whichs paths can be copied, separated by colons.
+  See <xref linkend="sec-sharing-packages" /> for details.  Each path
+  should be the <filename>/nix</filename> directory of a remote Nix
+  installation (i.e., not the <filename>/nix/store</filename>
+  directory).  The paths are subject to globbing, so you can set it so
+  something like <literal>/var/run/nix/remote-stores/*/nix</literal>
+  and mount multiple remote filesystems in
+  <literal>/var/run/nix/remote-stores</literal>.</para>
+
+  <para>Note that if you’re building through the <link
+  linkend="sec-nix-worker">Nix daemon</link>, the only setting for
+  this variable that matters is the one that the
+  <command>nix-worker</command> process uses.  So if you want to
+  change it, you have to restart the daemon.</para></listitem>
+
+</varlistentry>
+
+    
 </variablelist>
 
 

doc/manual/glossary.xml

@@ -74,9 +74,9 @@
 
 <glossentry><glossterm>Nix expression</glossterm>
 
-  <glossdef><para>A high-level description of software components and
+  <glossdef><para>A high-level description of software packages and
   compositions thereof.  Deploying software using Nix entails writing
-  Nix expressions for your components.  Nix expressions are translated
+  Nix expressions for your packages.  Nix expressions are translated
   to derivations that are stored in the Nix store.  These derivations
   can then be built.</para></glossdef>
 

doc/manual/installation.xml

@@ -6,29 +6,58 @@
 <title>Installation</title>
 
 
+<section><title>Supported platforms</title>
+
+<para>Nix is currently supported on the following platforms:
+
+<itemizedlist>
+
+  <listitem><para>Linux (particularly on x86, x86_64, and
+  PowerPC).</para></listitem>
+
+  <listitem><para>Mac OS X, both on Intel and
+  PowerPC.</para></listitem>
+
+  <listitem><para>FreeBSD (only tested on Intel).</para></listitem>
+
+  <listitem><para>Windows through <link
+  xlink:href="http://www.cygwin.com/">Cygwin</link>.</para>
+
+  <warning><para>On Cygwin, Nix <emphasis>must</emphasis> be installed
+  on an NTFS partition.  It will not work correctly on a FAT
+  partition.</para></warning>
+
+  </listitem>
+
+</itemizedlist>
+
+</para>
+
+<para>Nix is pretty portable, so it should work on most other Unix
+platforms as well.</para>
+
+</section>
+
+
 <section><title>Obtaining Nix</title>
 
 <para>The easiest way to obtain Nix is to download a <link
-xlink:href="http://www.cs.uu.nl/groups/ST/Trace/Nix">source
-distribution</link>.  RPMs for Red Hat, SuSE, and Fedora Core are also
-available.</para>
+xlink:href="http://nixos.org/">source distribution</link>.  RPMs
+for Red Hat, SuSE, and Fedora Core are also available.</para>
 
 <para>Alternatively, the most recent sources of Nix can be obtained
 from its <link
-xlink:href="https://svn.cs.uu.nl:12443/repos/trace/nix/trunk">Subversion
+xlink:href="https://svn.nixos.org/repos/nix/nix/trunk">Subversion
 repository</link>.  For example, the following command will check out
 the latest revision into a directory called
 <filename>nix</filename>:</para>
 
 <screen>
-$ svn checkout https://svn.cs.uu.nl:12443/repos/trace/nix/trunk nix</screen>
+$ svn checkout https://svn.nixos.org/repos/nix/nix/trunk nix</screen>
 
 <para>Likewise, specific releases can be obtained from the <link
-xlink:href="https://svn.cs.uu.nl:12443/repos/trace/nix/tags">tags
-directory</link> of the repository.  If you don't have Subversion, you
-can also download an automatically generated <link
-xlink:href="https://svn.cs.uu.nl:12443/dist/trace/">compressed
-tar-file</link> of the head revision of the trunk.</para>
+xlink:href="https://svn.nixos.org/repos/nix/nix/tags">tags
+directory</link> of the repository.</para>
 
 </section>
 
@@ -57,25 +86,33 @@ repository.</para>
 <para>To build the parser, very <emphasis>recent</emphasis> versions
 of Bison and Flex are required.  (This is because Nix needs GLR
 support in Bison and reentrancy support in Flex.)  For Bison, you need
-version 1.875c or higher (1.875 does <emphasis>not</emphasis> work),
-which can be obtained from the <link
-xlink:href="ftp://alpha.gnu.org/pub/gnu/bison">GNU FTP server</link>.
-For Flex, you need version 2.5.31, which is available on <link
-xlink:href="http://lex.sourceforge.net/">SourceForge</link>.  Slightly
-older versions may also work, but ancient versions like the ubiquitous
-2.5.4a won't.  Note that these are only required if you modify the
-parser or when you are building from the Subversion repository.</para>
+version 2.3 or higher (1.875 does <emphasis>not</emphasis> work),
+which can be obtained from
+the <link xlink:href="ftp://alpha.gnu.org/pub/gnu/bison">GNU FTP
+server</link>.  For Flex, you need version 2.5.33, which is available
+on <link xlink:href="http://lex.sourceforge.net/">SourceForge</link>.
+Slightly older versions may also work, but ancient versions like the
+ubiquitous 2.5.4a won't.  Note that these are only required if you
+modify the parser or when you are building from the Subversion
+repository.</para>
 
-<para>Nix uses Sleepycat's Berkeley DB and CWI's ATerm library.  These
-are included in the Nix source distribution.  If you build from the
-Subversion repository, you must download them yourself and place them
-in the <filename>externals/</filename> directory.  See
+<para>Nix uses CWI's ATerm library and the bzip2 compressor (including
+the bzip2 library).  These are included in the Nix source
+distribution.  If you build from the Subversion repository, you must
+download them yourself and place them in the
+<filename>externals/</filename> directory.  See
 <filename>externals/Makefile.am</filename> for the precise URLs of
 these packages.  Alternatively, if you already have them installed,
-you can use <command>configure</command>'s <option>--with-bdb</option>
-and <option>--with-aterm</option> options to point to their respective
-locations.  Note that Berkeley DB <emphasis>must</emphasis> be version
-4.4; other versions may not have compatible database formats.</para>
+you can use <command>configure</command>'s
+<option>--with-aterm</option> and <option>--with-bzip2</option>
+options to point to their respective locations.</para>
+
+<para>If you want to be able to upgrade Nix stores from before version
+0.12pre12020, you need Sleepycat's Berkeley DB version version 4.5.
+(Other versions may not have compatible database formats.).  Berkeley
+DB 4.5 is included in the Nix source distribution.  If you do not need
+this ability, you can build Nix with the
+<option>--disable-old-db-compat</option> configure option.</para>
 
 </section>
 
@@ -84,19 +121,21 @@ locations.  Note that Berkeley DB <emphasis>must</emphasis> be version
 
 <para>After unpacking or checking out the Nix sources, issue the
 following commands:
-    </para>
 
 <screen>
 $ ./configure <replaceable>options...</replaceable>
 $ make
 $ make install</screen>
 
+</para>
+
 <para>When building from the Subversion repository, these should be
 preceded by the command:
-    </para>
 
 <screen>
-$ autoreconf -i</screen>
+$ ./bootstrap</screen>
+
+</para>
 
 <para>The installation path can be specified by passing the
 <option>--prefix=<replaceable>prefix</replaceable></option> to
@@ -123,28 +162,32 @@ options.</para>
 
 <section><title>Installing from RPMs</title>
 
-<para>RPM packages of Nix can be downloaded from <uri
-xlink:href="http://www.cs.uu.nl/groups/ST/Trace/Nix">http://www.cs.uu.nl/groups/ST/Trace/Nix</uri>.
-These RPMs should work for most fairly recent releases of SuSE and Red
-Hat Linux.  They have been known to work work on SuSE Linux 8.1 and
-9.0, and Red Hat 9.0.  In fact, it should work on any RPM-based Linux
-distribution based on <literal>glibc</literal> 2.3 or later.</para>
+<para>RPM packages of Nix can be downloaded from <link
+xlink:href="http://nixos.org/" />.  These RPMs should work for most
+fairly recent releases of SuSE and Red Hat Linux.  They have been
+known to work work on SuSE Linux 8.1 and 9.0, and Red Hat 9.0.  In
+fact, it should work on any RPM-based Linux distribution based on
+<literal>glibc</literal> 2.3 or later.</para>
 
 <para>Once downloaded, the RPMs can be installed or upgraded using
-<command>rpm -U</command>.  For example,</para>
+<command>rpm -U</command>.  For example,
 
 <screen>
 $ rpm -U nix-0.5pre664-1.i386.rpm</screen>
 
+</para>
+
 <para>The RPMs install into the directory <filename>/nix</filename>.
 Nix can be uninstalled using <command>rpm -e nix</command>.  After
 this it will be necessary to manually remove the Nix store and other
-auxiliary data:</para>
+auxiliary data:
 
 <screen>
 $ rm -rf /nix/store
 $ rm -rf /nix/var</screen>
 
+</para>
+
 </section>
 
 
@@ -152,64 +195,262 @@ $ rm -rf /nix/var</screen>
 
 <para>You can install the latest stable version of Nix through Nix
 itself by subscribing to the channel <link
-xlink:href="http://nix.cs.uu.nl/dist/nix/channels-v3/nix-stable" /> ,
-or the latest unstable version by subscribing to the channel<link
-xlink:href="http://nix.cs.uu.nl/dist/nix/channels-v3/nix-unstable" />.
+xlink:href="http://nixos.org/releases/nix/channels/nix-stable" />,
+or the latest unstable version by subscribing to the channel <link
+xlink:href="http://nixos.org/releases/nix/channels/nix-unstable" />.
 You can also do a <link linkend="sec-one-click">one-click
 installation</link> by clicking on the package links at <link
-xlink:href="http://nix.cs.uu.nl/dist/nix/" />.</para>
+xlink:href="http://nixos.org/releases/full-index-nix.html" />.</para>
 
 </section>
 
 
-<section><title>Permissions</title>
+<section><title>Security</title>
 
-<para>All Nix operations must be performed under the user ID that owns
-the Nix store and database
-(<filename><replaceable>prefix</replaceable>/store</filename> and
-<filename><replaceable>prefix</replaceable>/var/nix/db</filename>,
-respectively).  When installed from the RPM packages, these
-directories are owned by <systemitem class="username">root</systemitem>.</para>
+<para>Nix has two basic security models.  First, it can be used in
+“single-user mode”, which is similar to what most other package
+management tools do: there is a single user (typically <systemitem
+class="username">root</systemitem>) who performs all package
+management operations.  All other users can then use the installed
+packages, but they cannot perform package management operations
+themselves.</para>
 
-<section><title>Setuid installation</title>
+<para>Alternatively, you can configure Nix in “multi-user mode”.  In
+this model, all users can perform package management operations — for
+instance, every user can install software without requiring root
+privileges.  Nix ensures that this is secure.  For instance, it’s not
+possible for one user to overwrite a package used by another user with
+a Trojan horse.</para>
 
-<para>As a somewhat <emphasis>ad hoc</emphasis> hack, you can also
-install the Nix binaries <quote>setuid</quote> so that a Nix store can
-be shared among several users.  To do this, configure Nix with the
-<emphasis>--enable-setuid</emphasis> option.  Nix will be installed as
-owned by a user and group specified by the
-<option>--with-nix-user=</option><parameter>user</parameter> and
-<option>--with-nix-group=</option><parameter>group</parameter>
-options.  E.g.,
 
-<screen>
-$ ./configure --enable-setuid --with-nix-user=my_nix_user --with-nix-group=my_nix_group</screen>
+<section><title>Single-user mode</title>
+  
+<para>In single-user mode, all Nix operations that access the database
+in <filename><replaceable>prefix</replaceable>/var/nix/db</filename>
+or modify the Nix store in
+<filename><replaceable>prefix</replaceable>/store</filename> must be
+performed under the user ID that owns those directories.  This is
+typically <systemitem class="username">root</systemitem>.  (If you
+install from RPM packages, that’s in fact the default ownership.)
+However, on single-user machines, it is often convenient to
+<command>chown</command> those directories to your normal user account
+so that you don’t have to <command>su</command> to <systemitem
+class="username">root</systemitem> all the time.</para>
 
-The user and group default to <literal>nix</literal>.  You should make
-sure that both the user and the group exist.  Any <quote>real</quote>
-users that you want to allow access should be added to the Nix
+</section>
+
+
+<section xml:id="ssec-multi-user"><title>Multi-user mode</title>
+
+<para>To allow a Nix store to be shared safely among multiple users,
+it is important that users are not able to run builders that modify
+the Nix store or database in arbitrary ways, or that interfere with
+builds started by other users.  If they could do so, they could
+install a Trojan horse in some package and compromise the accounts of
+other users.</para>
+
+<para>To prevent this, the Nix store and database are owned by some
+privileged user (usually <literal>root</literal>) and builders are
+executed under special user accounts (usually named
+<literal>nixbld1</literal>, <literal>nixbld2</literal>, etc.).  When a
+unprivileged user runs a Nix command, actions that operate on the Nix
+store (such as builds) are forwarded to a <emphasis>Nix
+daemon</emphasis> running under the owner of the Nix store/database
+that performs the operation.</para>
+
+<note><para>Multi-user mode has one important limitation: only
+<systemitem class="username">root</systemitem> can run <command
+linkend="sec-nix-pull">nix-pull</command> to register the availability
+of pre-built binaries.  However, those registrations are shared by all
+users, so they still get the benefit from <command>nix-pull</command>s
+done by <systemitem class="username">root</systemitem>.</para></note>
+
+
+<section><title>Setting up the build users</title>
+
+<para>The <emphasis>build users</emphasis> are the special UIDs under
+which builds are performed.  They should all be members of the
+<emphasis>build users group</emphasis> (usually called
+<literal>nixbld</literal>).  This group should have no other members.
+The build users should not be members of any other group.</para>
+
+<para>Here is a typical <filename>/etc/group</filename> definition of
+the build users group with 10 build users:
+
+<programlisting>
+nixbld:!:30000:nixbld1,nixbld2,nixbld3,nixbld4,nixbld5,nixbld6,nixbld7,nixbld8,nixbld9,nixbld10
+</programlisting>
+
+In this example the <literal>nixbld</literal> group has UID 30000, but
+of course it can be anything that doesn’t collide with an existing
 group.</para>
 
-<warning><para>A setuid installation should only by used if the users
-in the Nix group are mutually trusted, since any user in that group
-has the ability to change anything in the Nix store or database.  For
-instance, they could install a trojan horse in executables used by
-other users.</para></warning>
+<para>Here is the corresponding part of
+<filename>/etc/passwd</filename>:
 
-<warning><para>On some platforms, the Nix binaries will be installed
-as setuid <literal>root</literal>.  They drop root privileges
-immediately after startup and switch to the Nix user.  The reason for
-this is that both the real and effective user must be set to the Nix
-user, and POSIX has no system call to do this.  This is not the case
-on systems that have the <function>setresuid()</function> system call
-(such as Linux and FreeBSD), so on those systems the binaries are
-simply owned by the Nix user.</para></warning>
+<programlisting>
+nixbld1:x:30001:65534:Nix build user 1:/var/empty:/noshell
+nixbld2:x:30002:65534:Nix build user 2:/var/empty:/noshell
+nixbld3:x:30003:65534:Nix build user 3:/var/empty:/noshell
+...
+nixbld10:x:30010:65534:Nix build user 10:/var/empty:/noshell
+</programlisting>
+
+The home directory of the build users should not exist or should be an
+empty directory to which they do not have write access.</para>
+
+<para>The build users should have write access to the Nix store, but
+they should not have the right to delete files.  Thus the Nix store’s
+group should be the build users group, and it should have the sticky
+bit turned on (like <filename>/tmp</filename>):
+
+<screen>
+$ chgrp nixbld /nix/store
+$ chmod 1777 /nix/store
+</screen>
+
+</para>
+
+<para>Finally, you should tell Nix to use the build users by
+specifying the build users group in the <link
+linkend="conf-build-users-group"><literal>build-users-group</literal>
+option</link> in the <link linkend="sec-conf-file">Nix configuration
+file</link> (<literal>/nix/etc/nix/nix.conf</literal>):
+
+<programlisting>
+build-users-group = nixbld
+</programlisting>
+
+</para>
 
 </section>
 
+
+<section><title>Nix store/database owned by root</title>
+
+<para>The simplest setup is to let <literal>root</literal> own the Nix
+store and database.  I.e.,
+
+<screen>
+$ chown -R root /nix/store /nix/var/nix</screen>
+
+</para>
+
+<para>The <link linkend="sec-nix-worker">Nix daemon</link> should be
+started as follows (as <literal>root</literal>):
+
+<screen>
+$ nix-worker --daemon</screen>
+
+You’ll want to put that line somewhere in your system’s boot
+scripts.</para>
+
+<para>To let unprivileged users use the daemon, they should set the
+<link linkend="envar-remote"><envar>NIX_REMOTE</envar> environment
+variable</link> to <literal>daemon</literal>.  So you should put a
+line like
+
+<programlisting>
+export NIX_REMOTE=daemon</programlisting>
+
+into the users’ login scripts.</para>
+
 </section>
 
 
+<section><title>Nix store/database not owned by root</title>
+
+<para>It is also possible to let the Nix store and database be owned
+by a non-root user, which should be more secure<footnote><para>Note
+however that even when the Nix daemon runs as root, not
+<emphasis>that</emphasis> much code is executed as root: Nix
+expression evaluation is performed by the calling (unprivileged) user,
+and builds are performed under the special build user accounts.  So
+only the code that accesses the database and starts builds is executed
+as <literal>root</literal>.</para></footnote>.  Typically, this user
+is a special account called <literal>nix</literal>, but it can be
+named anything.  It should own the Nix store and database:
+
+<screen>
+$ chown -R root /nix/store /nix/var/nix</screen>
+
+and of course <command>nix-worker --daemon</command> should be started
+under that user, e.g.,
+
+<screen>
+$ su - nix -c "exec /nix/bin/nix-worker --daemon"</screen>
+
+</para>
+
+<para>There is a catch, though: non-<literal>root</literal> users
+cannot start builds under the build user accounts, since the
+<function>setuid</function> system call is obviously privileged.  To
+allow a non-<literal>root</literal> Nix daemon to use the build user
+feature, it calls a setuid-root helper program,
+<command>nix-setuid-helper</command>.  This program is installed in
+<filename><replaceable>prefix</replaceable>/libexec/nix-setuid-helper</filename>.
+To set the permissions properly (Nix’s <command>make install</command>
+doesn’t do this, since we don’t want to ship setuid-root programs
+out-of-the-box):
+
+<screen>
+$ chown root.root /nix/libexec/nix-setuid-helper
+$ chmod 4755 /nix/libexec/nix-setuid-helper
+</screen>
+
+(This example assumes that the Nix binaries are installed in
+<filename>/nix</filename>.)</para>
+
+<para>Of course, the <command>nix-setuid-helper</command> command
+should not be usable by just anybody, since then anybody could run
+commands under the Nix build user accounts.  For that reason there is
+a configuration file <filename>/etc/nix-setuid.conf</filename> that
+restricts the use of the helper.  This file should be a text file
+containing precisely two lines, the first being the Nix daemon user
+and the second being the build users group, e.g.,
+
+<programlisting>
+nix
+nixbld
+</programlisting>
+
+The setuid-helper barfs if it is called by a user other than the one
+specified on the first line, or if it is asked to execute a build
+under a user who is not a member of the group specified on the second
+line.  The file <filename>/etc/nix-setuid.conf</filename> must be
+owned by root, and must not be group- or world-writable.  The
+setuid-helper barfs if this is not the case.</para>
+
+</section>
+
+
+<section><title>Restricting access</title>
+
+<para>To limit which users can perform Nix operations, you can use the
+permissions on the directory
+<filename>/nix/var/nix/daemon-socket</filename>.  For instance, if you
+want to restrict the use of Nix to the members of a group called
+<literal>nix-users</literal>, do
+
+<screen>
+$ chgrp nix-users /nix/var/nix/daemon-socket
+$ chmod ug=rwx,o= /nix/var/nix/daemon-socket
+</screen>
+
+This way, users who are not in the <literal>nix-users</literal> group
+cannot connect to the Unix domain socket
+<filename>/nix/var/nix/daemon-socket/socket</filename>, so they cannot
+perform Nix operations.</para>
+
+</section>
+
+
+</section> <!-- end of multi-user -->
+
+
+</section> <!-- end of security -->
+
+
 <section><title>Using Nix</title>
 
 <para>To use Nix, some environment variables should be set.  In

doc/manual/introduction.xml

@@ -1,150 +1,337 @@
 <chapter xmlns="http://docbook.org/ns/docbook"
-         xmlns:xlink="http://www.w3.org/1999/xlink">
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="chap-introduction">
 
 <title>Introduction</title>
 
-<para>Nix is a system for the deployment of software.  Software
-deployment is concerned with the creation, distribution, and
-management of software components (<quote>packages</quote>).  Its main
-features are:
 
-<itemizedlist>
+<section><title>About Nix</title>
 
-<listitem><para>It helps you make sure that dependency specifications
-are complete.  In general in a deployment system you have to specify
-for each component what its dependencies are, but there are no
-guarantees that this specification is complete.  If you forget a
-dependency, then the component will build and work correctly on
-<emphasis>your</emphasis> machine if you have the dependency
-installed, but not on the end user's machine if it's not
-there.</para></listitem>
+<para>Nix is a <emphasis>purely functional package manager</emphasis>.
+This means that it treats packages like values in purely functional
+programming languages such as Haskell — they are built by functions
+that don’t have side-effects, and they never change after they have
+been built.  Nix stores packages in the <emphasis>Nix
+store</emphasis>, usually the directory
+<filename>/nix/store</filename>, where each package has its own unique
+subdirectory such as
 
-<listitem><para>It is possible to have <emphasis>multiple versions or
-variants</emphasis> of a component installed at the same time.  In
-contrast, in systems such as RPM different versions of the same
-package tend to install to the same location in the file system, so
-installing one version will remove the other.  This is especially
-important if you want to use applications that have conflicting
-requirements on different versions of a component (e.g., application A
-requires version 1.0 of library X, while application B requires a
-non-backwards compatible version 1.1).</para></listitem>
+<programlisting>
+/nix/store/r8vvq9kq18pz08v249h8my6r9vs7s0n3-firefox-2.0.0.1/
+</programlisting>
 
-<listitem><para>Users can have different <quote>views</quote>
-(<quote>profiles</quote> in Nix parlance) on the set of installed
-applications in a system.  For instance, one user can have version 1.0
-of some package visible, while another is using version 1.1, and a
-third doesn't use it at all.</para></listitem>
+where <literal>r8vvq9kq…</literal> is a unique identifier for the
+package that captures all its dependencies (it’s a cryptographic hash
+of the package’s build dependency graph).  This enables many powerful
+features.</para>
 
-<listitem><para>It is possible to atomically
-<emphasis>upgrade</emphasis> software.  I.e., there is no time window
-during an upgrade in which part of the old version and part of the new
-version are simultaneously visible (which might well cause the
-component to fail).</para></listitem>
 
-<listitem><para>Likewise, it is possible to atomically roll back after
-an install, upgrade, or uninstall action.  That is, in a fast (O(1))
-operation the previous configuration of the system can be restored.
-This is because upgrade or uninstall actions don't actually remove
-components from the system.</para></listitem>
+<simplesect><title>Multiple versions</title>
 
-<listitem><para>Unused components can be
-<emphasis>garbage-collected</emphasis> automatically and safely: when
-you remove an application from a profile, its dependencies will be
-deleted by the garbage collector only if there are no other active
-applications using them.</para></listitem>
+<para>You can have multiple versions or variants of a package
+installed at the same time.  This is especially important when
+different applications have dependencies on different versions of the
+same package — it prevents the “DLL hell”.  Because of the hashing
+scheme, different versions of a package end up in different paths in
+the Nix store, so they don’t interfere with each other.</para>
 
-<listitem><para>Nix supports both source-based deployment models
-(where you distribute <emphasis>Nix expressions</emphasis> that tell
-Nix how to build software from source) and binary-based deployment
-models.  The latter is more-or-less transparent: installation of
-components is always based on Nix expressions, but if the expressions
-have been built before and Nix knows that the resulting binaries are
-available somewhere, it will use those instead.</para></listitem>
+<para>An important consequence is that operations like upgrading or
+uninstalling an application cannot break other applications, since
+these operations never “destructively” update or delete files that are
+used by other packages.</para>
 
-<listitem><para>Nix is flexible in the deployment policies that it
-supports.  There is a clear separation between the tools that
-implement basic Nix <emphasis>mechanisms</emphasis> (e.g., building
-Nix expressions), and the tools that implement various deployment
-<emphasis>policies</emphasis>.  For instance, there is a concept of
-<quote>Nix channels</quote> that can be used to keep software
-installations up-to-date automatically from a network source.  This is
-a policy that is implemented by a fairly short Perl script, which can
-be adapted easily to achieve similar policies.</para></listitem>
+</simplesect>
 
-<listitem><para>Nix component builds aim to be <quote>pure</quote>;
-that is, unaffected by anything other than the declared dependencies.
-This means that if a component was built successfully once, it can be
-rebuilt again on another machine and the result will be the same.  We
-cannot <emphasis>guarantee</emphasis> this (e.g., if the build depends
-on the time-of-day), but Nix (and the tools in the Nix Packages
-collection) takes special care to help achieve this.</para></listitem>
 
-<listitem><para>Nix expressions (the things that tell Nix how to build
-components) are self-contained: they describe not just components but
-complete compositions.  In other words, Nix expressions also describe
-how to build all the dependencies.  This is in contrast to component
-specification languages like RPM spec files, which might say that a
-component X depends on some other component Y, but since it does not
-describe <emphasis>exactly</emphasis> what Y is, the result of
-building or running X might be different on different machines.
-Combined with purity, self-containedness ensures that a component that
-<quote>works</quote> on one machine also works on another, when
-deployed using Nix.</para></listitem>
+<simplesect><title>Complete dependencies</title>
 
-<listitem><para>The Nix expression language makes it easy to describe
-variability in components (e.g., optional features or
-dependencies).</para></listitem>
+<para>Nix helps you make sure that package dependency specifications
+are complete.  In general, when you’re making a package for a package
+management system like RPM, you have to specify for each package what
+its dependencies are, but there are no guarantees that this
+specification is complete.  If you forget a dependency, then the
+package will build and work correctly on <emphasis>your</emphasis>
+machine if you have the dependency installed, but not on the end
+user's machine if it's not there.</para>
 
-<listitem><para>Nix is ideal for building build farms that do
-continuous builds of software from a version management system, since
-it can take care of building all the dependencies as well.  Also, Nix
-only rebuilds components that have changed, so there are no
-unnecessary builds.  In addition, Nix can transparently distribute
-build jobs over different machines, including different
-platforms.</para></listitem>
+<para>Since Nix on the other hand doesn’t install packages in “global”
+locations like <filename>/usr/bin</filename> but in package-specific
+directories, the risk of incomplete dependencies is greatly reduced.
+This is because tools such as compilers don’t search in per-packages
+directories such as
+<filename>/nix/store/5lbfaxb722zp…-openssl-0.9.8d/include</filename>,
+so if a package builds correctly on your system, this is because you
+specified the dependency explicitly.</para>
 
-<listitem><para>Nix can be used not only for software deployment, but
-also for <emphasis>service deployment</emphasis>, such as the
-deployment of a complete web server with all its configuration files,
-static pages, software dependencies, and so on.  Nix's advantages for
-software deployment also apply here: for instance, the ability
-trivially to have multiple configurations at the same time, or the
-ability to do rollbacks.</para></listitem>
+<para>Runtime dependencies are found by scanning binaries for the hash
+parts of Nix store paths (such as <literal>r8vvq9kq…</literal>).  This
+sounds risky, but it works extremely well.</para>
 
-<listitem><para>Nix can efficiently upgrade between different versions
-of a component through <emphasis>binary patching</emphasis>.  If
-patches are available on a server, and you try to install a new
-version of some component, Nix will automatically apply a patch (or
-sequence of patches), if available, to transform the installed
-component into the new version.</para></listitem> 
+</simplesect>
 
-</itemizedlist>
 
-</para>
+<simplesect><title>Multi-user support</title>
+
+<para>Starting at version 0.11, Nix has multi-user support.  This
+means that non-privileged users can securely install software.  Each
+user can have a different <emphasis>profile</emphasis>, a set of
+packages in the Nix store that appear in the user’s
+<envar>PATH</envar>.  If a user installs a package that another user
+has already installed previously, the package won’t be built or
+downloaded a second time.  At the same time, it is not possible for
+one user to inject a Trojan horse into a package that might be used by
+another user.</para>
+
+<!--
+<para>More details can be found in Section 3 of our <a
+href="docs/papers.html#securesharing">ASE 2005 paper</a>.</para>
+-->
+
+</simplesect>
+
+
+<simplesect><title>Atomic upgrades and rollbacks</title>
+
+<para>Since package management operations never overwrite packages in
+the Nix store but just add new versions in different paths, they are
+<emphasis>atomic</emphasis>.  So during a package upgrade, there is no
+time window in which the package has some files from the old version
+and some files from the new version — which would be bad because a
+program might well crash if it’s started during that period.</para>
+
+<para>And since package aren’t overwritten, the old versions are still
+there after an upgrade.  This means that you can <emphasis>roll
+back</emphasis> to the old version:</para>
+
+<screen>
+$ nix-env --upgrade <replaceable>some-packages</replaceable>
+$ nix-env --rollback
+</screen>
+
+</simplesect>
+
+
+<simplesect><title>Garbage collection</title>
+
+<para>When you install a package like this…
+
+<screen>
+$ nix-env --uninstall firefox
+</screen>
+
+the package isn’t deleted from the system right away (after all, you
+might want to do a rollback, or it might be in the profiles of other
+users).  Instead, unused packages can be deleted safely by running the
+<emphasis>garbage collector</emphasis>:
+
+<screen>
+$ nix-collect-garbage
+</screen>
+
+This deletes all packages that aren’t in use by any user profile or by
+a currently running program.</para>
+
+</simplesect>
+
+
+<simplesect><title>Functional package language</title>
+
+<para>Packages are built from <emphasis>Nix expressions</emphasis>,
+which is a simple functional language.  A Nix expression describes
+everything that goes into a package build action (a “derivation”):
+other packages, sources, the build script, environment variables for
+the build script, etc.  Nix tries very hard to ensure that Nix
+expressions are <emphasis>deterministic</emphasis>: building a Nix
+expression twice should yield the same result.</para>
+
+<para>Because it’s a functional language, it’s easy to support
+building variants of a package: turn the Nix expression into a
+function and call it any number of times with the appropriate
+arguments.  Due to the hashing scheme, variants don’t conflict with
+each other in the Nix store.</para>
+
+</simplesect>
+
+
+<simplesect><title>Transparent source/binary deployment</title>
+
+<para>Nix expressions generally describe how to build a package from
+source, so an installation action like
+
+<screen>
+$ nix-env --install firefox
+</screen>
+
+<emphasis>could</emphasis> cause quite a bit of build activity, as not
+only Firefox but also all its dependencies (all the way up to the C
+library and the compiler) would have to built, at least if they are
+not already in the Nix store.  This is a <emphasis>source deployment
+model</emphasis>.  For most users, building from source is not very
+pleasant as it takes far too long.  However, Nix can automatically
+skip building from source and download a pre-built binary instead if
+it knows about it.  <emphasis>Nix channels</emphasis> provide Nix
+expressions along with pre-built binaries.</para>
+
+<!--
+<para>source deployment model (like <a
+href="http://www.gentoo.org/">Gentoo</a>) and a binary model (like
+RPM)</para>
+-->
+
+</simplesect>
+
+
+<simplesect><title>Binary patching</title>
+
+<para>In addition to downloading binaries automatically if they’re
+available, Nix can download binary deltas that patch an existing
+package in the Nix store into a new version.  This speeds up
+upgrades.</para>
+
+</simplesect>
+
+
+<simplesect><title>Nix Packages collection</title>
+
+<para>We provide a large set of Nix expressions containing hundreds of
+existing Unix packages, the <emphasis>Nix Packages
+collection</emphasis> (Nixpkgs).</para>
+
+</simplesect>
+
+
+<simplesect><title>Service deployment</title>
+
+<para>Nix can be used not only for rolling out packages, but also
+complete <emphasis>configurations</emphasis> of services.  This is
+done by treating all the static bits of a service (such as software
+packages, configuration files, control scripts, static web pages,
+etc.) as “packages” that can be built by Nix expressions.  As a
+result, all the features above apply to services as well: for
+instance, you can roll back a web server configuration if a
+configuration change turns out to be undesirable, you can easily have
+multiple instances of a service (e.g., a test and production server),
+and because the whole service is built in a purely functional way from
+a Nix expression, it is repeatable so you can easily reproduce the
+service on another machine.</para>
+
+<!--
+<para>You can read more about this in our <a
+href="docs/papers.html#servicecm">SCM-12 paper</a>.</para>
+-->
+
+</simplesect>
+
+
+<simplesect><title>Portability</title>
+
+<para>Nix should run on most Unix systems, including Linux, FreeBSD and
+Mac OS X.  It is also supported on Windows using Cygwin.</para>
+
+</simplesect>
+
+
+<simplesect><title>NixOS</title>
+
+<para>NixOS is a Linux distribution based on Nix.  It uses Nix not
+just for package management but also to manage the system
+configuration (e.g., to build configuration files in
+<filename>/etc</filename>).  This means, among other things, that it’s
+possible to easily roll back the entire configuration of the system to
+an earlier state.  Also, users can install software without root
+privileges.  For more information and downloads, see the <link
+xlink:href="http://nixos.org/">NixOS homepage</link>.</para>
+
+</simplesect>
+
+
+<!-- other features:
+
+- build farms
+- reproducibility (Nix expressions allows whole configuration to be rebuilt)
+
+-->
+
+</section>
+
+
+<section><title>About us</title>
+
+<para>Nix was originally developed at the <link
+xlink:href="http://www.cs.uu.nl/">Department of Information and
+Computing Sciences</link>, Utrecht University by the <link
+xlink:href="http://www.cs.uu.nl/wiki/Trace/WebHome">TraCE
+project</link> (2003-2008).  The project was funded by the Software
+Engineering Research Program <link
+xlink:href="http://www.jacquard.nl/">Jacquard</link> to improve the
+support for variability in software systems.  Further funding is now
+provided by the NIRICT LaQuSo Build Farm project.</para>
+
+</section>
+
+
+<section><title>About this manual</title>
 
 <para>This manual tells you how to install and use Nix and how to
 write Nix expressions for software not already in the Nix Packages
 collection.  It also discusses some advanced topics, such as setting
-up a Nix-based build farm, and doing service deployment using
-Nix.</para>
+up a Nix-based build farm.</para>
 
-<note><para>Some background information on Nix can be found in a
-number of papers.  The ICSE 2004 paper <citetitle
-xlink:href='http://www.cs.uu.nl/~eelco/pubs/immdsd-icse2004-final.pdf'>Imposing
+</section>
+
+
+<section><title>License</title>
+
+<para>Nix is free software; you can redistribute it and/or modify it
+under the terms of the <link
+xlink:href="http://www.gnu.org/licenses/lgpl.html">GNU Lesser General
+Public License</link> as published by the <link
+xlink:href="http://www.fsf.org/">Free Software Foundation</link>;
+either version 2.1 of the License, or (at your option) any later
+version.  Nix is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.</para>
+
+</section>
+
+
+<section><title>More information</title>
+
+<para>Some background information on Nix can be found in a number of
+papers.  The ICSE 2004 paper <citetitle
+xlink:href='http://www.st.ewi.tudelft.nl/~dolstra/pubs/immdsd-icse2004-final.pdf'>Imposing
 a Memory Management Discipline on Software Deployment</citetitle>
 discusses the hashing mechanism used to ensure reliable dependency
 identification and non-interference between different versions and
 variants of packages.  The LISA 2004 paper <citetitle
-xlink:href='http://www.cs.uu.nl/~eelco/pubs/nspfssd-lisa2004-final.pdf'>Nix:
+xlink:href='http://www.st.ewi.tudelft.nl/~dolstra/pubs/nspfssd-lisa2004-final.pdf'>Nix:
 A Safe and Policy-Free System for Software Deployment</citetitle>
 gives a more general discussion of Nix from a system-administration
 perspective.  The CBSE 2005 paper <citetitle
-xlink:href='http://www.cs.uu.nl/~eelco/pubs/eupfcdm-cbse2005-final.pdf'>Efficient
+xlink:href='http://www.st.ewi.tudelft.nl/~dolstra/pubs/eupfcdm-cbse2005-final.pdf'>Efficient
 Upgrading in a Purely Functional Component Deployment Model
-</citetitle> is about transparent patch deployment in Nix.  Finally,
-the SCM-12 paper <citetitle
-xlink:href='http://www.cs.uu.nl/~eelco/pubs/servicecm-scm12-final.pdf'>
+</citetitle> is about transparent patch deployment in Nix.  The SCM-12
+paper <citetitle
+xlink:href='http://www.st.ewi.tudelft.nl/~dolstra/pubs/servicecm-scm12-final.pdf'>
 Service Configuration Management</citetitle> shows how services (e.g.,
-web servers) can be deployed and managed through Nix.</para></note>
+web servers) can be deployed and managed through Nix.  A short
+overview of NixOS is given in the HotOS XI paper <citetitle
+xlink:href="http://www.st.ewi.tudelft.nl/~dolstra/pubs/hotos-final.pdf">Purely
+Functional System Configuration Management</citetitle>.  The Nix
+homepage has <link
+xlink:href="http://nix.cs.uu.nl/docs/papers.html">an up-to-date list
+of Nix-related papers</link>.</para>
+
+<para>Nix is the subject of Eelco Dolstra’s PhD thesis <citetitle
+xlink:href="http://igitur-archive.library.uu.nl/dissertations/2006-0118-200031/index.htm">The
+Purely Functional Software Deployment Model</citetitle>, which
+contains most of the papers listed above.</para>
+
+<para>Nix has a homepage at <link
+xlink:href="http://nixos.org/"/>.</para>
+
+</section>
+
 
 </chapter>

doc/manual/manual.xml

@@ -13,14 +13,22 @@
         <firstname>Eelco</firstname>
         <surname>Dolstra</surname>
       </personname>
+      <affiliation>
+        <orgname>Delft University of Technology</orgname>
+        <orgdiv>Department of Software Technology</orgdiv>
+      </affiliation>
     </author>
 
     <copyright>
       <year>2004</year>
       <year>2005</year>
       <year>2006</year>
+      <year>2007</year>
+      <year>2008</year>
       <holder>Eelco Dolstra</holder>
     </copyright>
+
+    <date>November 2008</date>
     
   </info>
 
@@ -49,7 +57,7 @@
         <title>nix-instantiate</title>
         <xi:include href="nix-instantiate.xml" />
       </section>
-      <section>
+      <section xml:id="sec-nix-store">
         <title>nix-store</title>
         <xi:include href="nix-store.xml" />
       </section>
@@ -65,10 +73,14 @@
         <title>nix-channel</title>
         <xi:include href="nix-channel.xml" />
       </section>
-      <section>
+      <section xml:id="sec-nix-collect-garbage">
         <title>nix-collect-garbage</title>
         <xi:include href="nix-collect-garbage.xml" />
       </section>
+      <section xml:id="sec-nix-copy-closure">
+        <title>nix-copy-closure</title>
+        <xi:include href="nix-copy-closure.xml" />
+      </section>
       <section xml:id="sec-nix-hash">
         <title>nix-hash</title>
         <xi:include href="nix-hash.xml" />
@@ -77,15 +89,11 @@
         <title>nix-install-package</title>
         <xi:include href="nix-install-package.xml" />
       </section>
-      <section>
-        <title>nix-pack-closure</title>
-        <xi:include href="nix-pack-closure.xml" />
-      </section>
-      <section>
+      <section xml:id="sec-nix-prefetch-url">
         <title>nix-prefetch-url</title>
         <xi:include href="nix-prefetch-url.xml" />
       </section>
-      <section>
+      <section xml:id="sec-nix-pull">
         <title>nix-pull</title>
         <xi:include href="nix-pull.xml" />
       </section>
@@ -93,16 +101,16 @@
         <title>nix-push</title>
         <xi:include href="nix-push.xml" />
       </section>
-      <section>
-        <title>nix-unpack-closure</title>
-        <xi:include href="nix-unpack-closure.xml" />
+      <section xml:id="sec-nix-worker">
+        <title>nix-worker</title>
+        <xi:include href="nix-worker.xml" />
       </section>
     </section>
     
   </appendix>
 
   <xi:include href="troubleshooting.xml" />
-  <xi:include href="bugs.xml" />
+  <!-- <xi:include href="bugs.xml" /> -->
   <xi:include href="glossary.xml" />
 
   <appendix>

doc/manual/nix-build.xml

@@ -1,5 +1,13 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+
+<refmeta>
+  <refentrytitle>nix-build</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
 
 <refnamediv>
   <refname>nix-build</refname>
@@ -9,8 +17,9 @@
 <refsynopsisdiv>
   <cmdsynopsis>
     <command>nix-build</command>
-    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xpointer(/nop/*)" />
+    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
     <arg><option>--arg</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
+    <arg><option>--argstr</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
     <arg>
       <group choice='req'>
         <arg choice='plain'><option>--attr</option></arg>

doc/manual/nix-channel.xml

@@ -1,6 +1,14 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
+<refmeta>
+  <refentrytitle>nix-channel</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
+
 <refnamediv>
   <refname>nix-channel</refname>
   <refpurpose>manage Nix channels</refpurpose>
@@ -54,11 +62,11 @@ also <xref linkend="sec-channels" />.</para>
   <varlistentry><term><option>--update</option></term>
 
     <listitem><para>Downloads the Nix expressions of all subscribed
-    channels, makes the conjunction of these the default for
-    <command>nix-env</command> operations (by calling <command>nix-env
-    -I</command>), and performs a <command>nix-pull</command> on the
-    manifests of all channels to make pre-built binaries
-    available.</para></listitem>
+    channels, makes them the default for <command>nix-env</command>
+    operations (by symlinking them in the directory
+    <filename>~/.nix-defexpr</filename>), and performs a
+    <command>nix-pull</command> on the manifests of all channels to
+    make pre-built binaries available.</para></listitem>
 
   </varlistentry>
 

doc/manual/nix-collect-garbage.xml

@@ -1,6 +1,14 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
+<refmeta>
+  <refentrytitle>nix-collect-garbage</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
+
 <refnamediv>
   <refname>nix-collect-garbage</refname>
   <refpurpose>delete unreachable store paths</refpurpose>

doc/manual/nix-copy-closure.xml

@@ -0,0 +1,151 @@
+<refentry xmlns="http://docbook.org/ns/docbook"
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+
+<refmeta>
+  <refentrytitle>nix-copy-closure</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
+
+<refnamediv>
+  <refname>nix-copy-closure</refname>
+  <refpurpose>copy a closure to or from a remote machine via SSH</refpurpose>
+</refnamediv>
+
+<refsynopsisdiv>
+  <cmdsynopsis>
+    <command>nix-copy-closure</command>
+    <group>
+      <arg choice='plain'><option>--to</option></arg>
+      <arg choice='plain'><option>--from</option></arg>
+    </group>
+    <arg><option>--sign</option></arg>
+    <arg><option>--gzip</option></arg>
+    <arg choice='plain'>
+      <arg><replaceable>user@</replaceable></arg><replaceable>machine</replaceable>
+    </arg>
+    <arg choice='plain'><replaceable>paths</replaceable></arg>
+  </cmdsynopsis>
+</refsynopsisdiv>
+
+
+<refsection><title>Description</title>
+
+<para><command>nix-copy-closure</command> gives you an easy and
+efficient way to exchange software between machines.  Given one or
+more Nix store paths <replaceable>paths</replaceable> on the local
+machine, <command>nix-copy-closure</command> computes the closure of
+those paths (i.e. all their dependencies in the Nix store), and copies
+all paths in the closure to the remote machine via the
+<command>ssh</command> (Secure Shell) command.  With the
+<option>--from</option>, the direction is reversed:
+the closure of <replaceable>paths</replaceable> on a remote machine is
+copied to the Nix store on the local machine.</para>
+
+<para>This command is efficient because it only sends the store paths
+that are missing on the target machine.</para>
+
+<para>Since <command>nix-copy-closure</command> calls
+<command>ssh</command>, you may be asked to type in the appropriate
+password or passphrase.  In fact, you may be asked
+<emphasis>twice</emphasis> because <command>nix-copy-closure</command>
+currently connects twice to the remote machine, first to get the set
+of paths missing on the target machine, and second to send the dump of
+those paths.  If this bothers you, use
+<command>ssh-agent</command>.</para>
+
+
+<refsection><title>Options</title>
+
+<variablelist>
+  
+  <varlistentry><term><option>--to</option></term>
+
+    <listitem><para>Copy the closure of
+    <replaceable>paths</replaceable> from the local Nix store to the
+    Nix store on <replaceable>machine</replaceable>.  This is the
+    default.</para></listitem>
+
+  </varlistentry>
+
+  <varlistentry><term><option>--from</option></term>
+
+    <listitem><para>Copy the closure of
+    <replaceable>paths</replaceable> from the Nix store on
+    <replaceable>machine</replaceable> to the local Nix
+    store.</para></listitem>
+
+  </varlistentry>
+
+  <varlistentry><term><option>--sign</option></term>
+
+    <listitem><para>Let the sending machine cryptographically sign the
+    dump of each path with the key in
+    <filename>/nix/etc/nix/signing-key.sec</filename>.  If the user on
+    the target machine does not have direct access to the Nix store
+    (i.e., if the target machine has a multi-user Nix installation),
+    then the target machine will check the dump against
+    <filename>/nix/etc/nix/signing-key.pub</filename> before unpacking
+    it in its Nix store.  This allows secure sharing of store paths
+    between untrusted users on two machines, provided that there is a
+    trust relation between the Nix installations on both machines
+    (namely, they have matching public/secret keys).</para></listitem>
+
+  </varlistentry>
+
+  <varlistentry><term><option>--gzip</option></term>
+
+    <listitem><para>Compress the dump of each path with
+    <command>gzip</command> before sending it.</para></listitem>
+
+  </varlistentry>
+
+</variablelist>
+
+</refsection>
+
+
+<refsection><title>Environment variables</title>
+
+<variablelist>
+
+  <varlistentry><term><envar>NIX_SSHOPTS</envar></term>
+
+    <listitem><para>Additional options to be passed to
+    <command>ssh</command> on the command line.</para></listitem>
+
+  </varlistentry>
+  
+</variablelist>
+
+</refsection>
+
+
+<refsection><title>Examples</title>
+
+<para>Copy Firefox with all its dependencies to a remote machine:
+
+<screen>
+$ nix-copy-closure --to alice@itchy.labs $(type -tP firefox)</screen>
+
+</para>
+
+<para>Copy Subversion from a remote machine and then install it into a
+user environment:
+
+<screen>
+$ nix-copy-closure --from alice@itchy.labs \
+    /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy-subversion-1.4.4
+$ nix-env -i /nix/store/0dj0503hjxy5mbwlafv1rsbdiyx1gkdy-subversion-1.4.4
+</screen>
+
+</para>
+
+</refsection>
+
+
+</refsection>
+
+</refentry>

doc/manual/nix-env.xml

@@ -1,6 +1,14 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
+<refmeta>
+  <refentrytitle>nix-env</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
+
 <refnamediv>
   <refname>nix-env</refname>
   <refpurpose>manipulate or query Nix user environments</refpurpose>
@@ -9,15 +17,9 @@
 <refsynopsisdiv>
   <cmdsynopsis>
     <command>nix-env</command>
-    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xpointer(/nop/*)" />
+    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
     <arg><option>--arg</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
-    <arg>
-      <group choice='req'>
-        <arg choice='plain'><option>--attr</option></arg>
-        <arg choice='plain'><option>-A</option></arg>
-      </group>
-      <replaceable>attrPath</replaceable>
-    </arg>
+    <arg><option>--argstr</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
     <arg>
       <group choice='req'>
         <arg choice='plain'><option>--file</option></arg>
@@ -37,9 +39,6 @@
       <replaceable>system</replaceable>
     </arg>
     <arg><option>--dry-run</option></arg>
-    <arg><option>--from-expression</option></arg>
-    <arg><option>-E</option></arg>
-    <arg><option>--from-profile</option> <replaceable>path</replaceable></arg>
     <arg choice='plain'><replaceable>operation</replaceable></arg>
     <arg rep='repeat'><replaceable>options</replaceable></arg>
     <arg rep='repeat'><replaceable>arguments</replaceable></arg>
@@ -50,7 +49,7 @@
 <refsection><title>Description</title>
 
 <para>The command <command>nix-env</command> is used to manipulate Nix
-user environments.  User environments are sets of software components
+user environments.  User environments are sets of software packages
 available to a user at some point in time.  In other words, they are a
 synthesised view of the programs available in the Nix store.  There
 may be many user environments: different users can have different
@@ -142,14 +141,34 @@ linkend="sec-common-options" />.</para>
 <variablelist>
 
   <varlistentry><term><filename>~/.nix-defexpr</filename></term>
-  
-    <listitem><para>The default Nix expression used by the
-    <option>--install</option>, <option>--upgrade</option>, and
-    <option>--query --available</option> operations to obtain
-    derivations.  It is generally a symbolic link to some other
-    location set using the <option>--import</option> operation.  The
+
+    <listitem><para>A directory that contains the default Nix
+    expressions used by the <option>--install</option>,
+    <option>--upgrade</option>, and <option>--query
+    --available</option> operations to obtain derivations.  The
     <option>--file</option> option may be used to override this
-    default.</para></listitem>
+    default.</para>
+
+    <para>The Nix expressions in this directory are combined into a
+    single attribute set, with each file as an attribute that has the
+    name of the file.  Thus, if <filename>~/.nix-defexpr</filename>
+    contains two files, <filename>foo</filename> and
+    <filename>bar</filename>, then the default Nix expression will
+    essentially be
+
+<programlisting>
+{
+  foo = import ~/.nix-defexpr/foo;
+  bar = import ~/.nix-defexpr/bar;
+}</programlisting>
+
+    </para>
+
+    <para>The command <command>nix-channel</command> places symlinks
+    to the downloaded Nix expressions from each subscribed channel in
+    this directory.</para>
+
+    </listitem>
     
   </varlistentry>
 
@@ -182,6 +201,7 @@ linkend="sec-common-options" />.</para>
     <arg choice='plain'><option>--install</option></arg>
     <arg choice='plain'><option>-i</option></arg>
   </group>
+  <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-inst-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
   <group choice='opt'>
     <arg choice='plain'><option>--preserve-installed</option></arg>
     <arg choice='plain'><option>-P</option></arg>
@@ -213,11 +233,21 @@ number of possible ways:
   <para>If there are multiple derivations matching a name in
   <replaceable>args</replaceable> that have the same name (e.g.,
   <literal>gcc-3.3.6</literal> and <literal>gcc-4.1.1</literal>), then
-  only the highest version will be installed.  You can force the
-  installation of multiple derivations with the same name by being
-  specific about the versions.  For instance, <literal>nix-env -i
-  gcc-3.3.6 gcc-4.1.1</literal> will install both version of GCC (and
-  will probably cause a user environment conflict!).</para></listitem>
+  the derivation with the highest <emphasis>priority</emphasis> is
+  used.  A derivation can define a priority by declaring the
+  <varname>meta.priority</varname> attribute.  This attribute should
+  be a number, with a higher value denoting a lower priority.  The
+  default priority is <literal>0</literal>.</para>
+
+  <para>If there are multiple matching derivations with the same
+  priority, then the derivation with the highest version will be
+  installed.</para>
+
+  <para>You can force the installation of multiple derivations with
+  the same name by being specific about the versions.  For instance,
+  <literal>nix-env -i gcc-3.3.6 gcc-4.1.1</literal> will install both
+  version of GCC (and will probably cause a user environment
+  conflict!).</para></listitem>
 
   <listitem><para>If <link
   linkend='opt-attr'><option>--attr</option></link>
@@ -264,6 +294,15 @@ number of possible ways:
 
 <variablelist>
 
+  <varlistentry><term><option>--prebuild-only</option> / <option>-b</option></term>
+
+    <listitem><para>Use only derivations for which a substitute is
+    registered, i.e., there is a pre-built binary available that can
+    be downloaded in lieu of building the derivation.  Thus, no
+    packages will be built from source.</para></listitem>
+
+  </varlistentry>
+
   <varlistentry><term><option>--preserve-installed</option></term>
     <term><option>-P</option></term>
   
@@ -379,7 +418,7 @@ the following paths will be substituted:
   
 <!--######################################################################-->
 
-<refsection><title>Operation <option>--upgrade</option></title>
+<refsection xml:id="rsec-nix-env-upgrade"><title>Operation <option>--upgrade</option></title>
 
 <refsection><title>Synopsis</title>
 
@@ -389,6 +428,7 @@ the following paths will be substituted:
     <arg choice='plain'><option>--upgrade</option></arg>
     <arg choice='plain'><option>-u</option></arg>
   </group>
+  <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-inst-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
   <group choice='opt'>
     <arg choice='plain'><option>--lt</option></arg>
     <arg choice='plain'><option>--leq</option></arg>
@@ -463,6 +503,9 @@ installed.</para>
 
 </variablelist>
 
+<para>For the other flags, see <option
+linkend="rsec-nix-env-install">--install</option>.</para>
+
 </refsection>
 
 <refsection><title>Examples</title>
@@ -483,7 +526,7 @@ upgrading `mozilla-1.2' to `mozilla-1.4'</screen>
 
 </refsection>
     
-<refsection><title>Versions</title>
+<refsection xml:id="ssec-version-comparisons"><title>Versions</title>
 
 <para>The upgrade operation determines whether a derivation
 <varname>y</varname> is an upgrade of a derivation
@@ -572,6 +615,111 @@ $ nix-env -e '*' <lineannotation>(remove everything)</lineannotation></screen>
 
 
   
+<!--######################################################################-->
+
+<refsection xml:id="rsec-nix-env-set-flag"><title>Operation <option>--set-flag</option></title>
+
+<refsection><title>Synopsis</title>
+
+<cmdsynopsis>
+  <command>nix-env</command>
+  <arg choice='plain'><option>--set-flag</option></arg>
+  <arg choice='plain'><replaceable>name</replaceable></arg>
+  <arg choice='plain'><replaceable>value</replaceable></arg>
+  <arg choice='plain' rep='repeat'><replaceable>drvnames</replaceable></arg>
+</cmdsynopsis>
+</refsection>
+
+<refsection><title>Description</title>
+            
+<para>The <option>--set-flag</option> operation allows meta attributes
+of installed packages to be modified.  There are several attributes
+that can be usefully modified, because they affect the behaviour of
+<command>nix-env</command> or the user environment build
+script:
+
+<itemizedlist>
+
+  <listitem><para><varname>priority</varname> can be changed to
+  resolve filename clashes.  The user environment build script uses
+  the <varname>meta.priority</varname> attribute of derivations to
+  resolve filename collisions between packages.  Lower priority values
+  denote a higher priority.  For instance, the GCC wrapper package and
+  the Binutils package in Nixpkgs both have a file
+  <filename>bin/ld</filename>, so previously if you tried to install
+  both you would get a collision.  Now, on the other hand, the GCC
+  wrapper declares a higher priority than Binutils, so the former’s
+  <filename>bin/ld</filename> is symlinked in the user
+  environment.</para></listitem>
+
+  <listitem><para><varname>keep</varname> can be set to
+  <literal>true</literal> to prevent the package from being upgraded
+  or replaced.  This is useful if you want to hang on to an older
+  version of a package.</para></listitem>
+
+  <listitem><para><varname>active</varname> can be set to
+  <literal>false</literal> to “disable” the package.  That is, no
+  symlinks will be generated to the files of the package, but it
+  remains part of the profile (so it won’t be garbage-collected).  It
+  can be set back to <literal>true</literal> to re-enable the
+  package.</para></listitem>
+
+</itemizedlist>
+
+</para>
+
+</refsection>
+            
+<refsection><title>Examples</title>
+
+<para>To prevent the currently installed Firefox from being upgraded:
+
+<screen>
+$ nix-env --set-flag keep true firefox</screen>
+
+After this, <command>nix-env -u</command> will ignore Firefox.</para>
+
+<para>To disable the currently installed Firefox, then install a new
+Firefox while the old remains part of the profile:
+
+<screen>
+$ nix-env -q \*
+firefox-2.0.0.9 <lineannotation>(the current one)</lineannotation>
+
+$ nix-env --preserve-installed -i firefox-2.0.0.11
+installing `firefox-2.0.0.11'
+building path(s) `/nix/store/myy0y59q3ig70dgq37jqwg1j0rsapzsl-user-environment'
+Collission between `/nix/store/<replaceable>...</replaceable>-firefox-2.0.0.11/bin/firefox'
+  and `/nix/store/<replaceable>...</replaceable>-firefox-2.0.0.9/bin/firefox'.
+<lineannotation>(i.e., can’t have two active at the same time)</lineannotation>
+
+$ nix-env --set-flag active false firefox
+setting flag on `firefox-2.0.0.9'
+
+$ nix-env --preserve-installed -i firefox-2.0.0.11
+installing `firefox-2.0.0.11'
+
+$ nix-env -q \*
+firefox-2.0.0.11 <lineannotation>(the enabled one)</lineannotation>
+firefox-2.0.0.9 <lineannotation>(the disabled one)</lineannotation></screen>
+
+</para>
+
+<para>To make files from <literal>binutils</literal> take precedence
+over files from <literal>gcc</literal>:
+
+<screen>
+$ nix-env --set-flag priority 5 binutils
+$ nix-env --set-flag priority 10 gcc</screen>
+
+</para>
+
+</refsection>
+    
+</refsection>
+
+
+  
 <!--######################################################################-->
   
 <refsection><title>Operation <option>--query</option></title>
@@ -584,13 +732,14 @@ $ nix-env -e '*' <lineannotation>(remove everything)</lineannotation></screen>
     <arg choice='plain'><option>--query</option></arg>
     <arg choice='plain'><option>-q</option></arg>
   </group>
-  <arg><option>--xml</option></arg>
   <group choice='opt'>
     <arg choice='plain'><option>--installed</option></arg>
     <arg choice='plain'><option>--available</option></arg>
     <arg choice='plain'><option>-a</option></arg>
   </group>
+  
   <sbr />
+  
   <arg>
     <group choice='req'>
       <arg choice='plain'><option>--status</option></arg>
@@ -599,8 +748,8 @@ $ nix-env -e '*' <lineannotation>(remove everything)</lineannotation></screen>
   </arg>
   <arg>
     <group choice='req'>
-      <arg choice='plain'><option>--attr</option></arg>
-      <arg choice='plain'><option>-A</option></arg>
+      <arg choice='plain'><option>--attr-path</option></arg>
+      <arg choice='plain'><option>-P</option></arg>
     </group>
   </arg>
   <arg><option>--no-name</option></arg>
@@ -614,6 +763,28 @@ $ nix-env -e '*' <lineannotation>(remove everything)</lineannotation></screen>
   <arg><option>--drv-path</option></arg>
   <arg><option>--out-path</option></arg>
   <arg><option>--description</option></arg>
+  <arg><option>--meta</option></arg>
+
+  <sbr />
+
+  <arg><option>--xml</option></arg>
+  <arg>
+    <group choice='req'>
+      <arg choice='plain'><option>--prebuilt-only</option></arg>
+      <arg choice='plain'><option>-b</option></arg>
+    </group>
+  </arg>
+
+  <arg>
+    <group choice='req'>
+      <arg choice='plain'><option>--attr</option></arg>
+      <arg choice='plain'><option>-A</option></arg>
+    </group>
+    <replaceable>attribute-path</replaceable>
+  </arg>
+
+  <sbr />
+  
   <arg choice='plain' rep='repeat'><replaceable>names</replaceable></arg>
 </cmdsynopsis>
 
@@ -690,6 +861,16 @@ user environment elements, etc. -->
 
   </varlistentry>
 
+  <varlistentry><term><option>--prebuild-only</option> / <option>-b</option></term>
+
+    <listitem><para>Show only derivations for which a substitute is
+    registered, i.e., there is a pre-built binary available that can
+    be downloaded in lieu of building the derivation.  Thus, this
+    shows all packages that probably can be installed
+    quickly.</para></listitem>
+
+  </varlistentry>
+
   <varlistentry><term><option>--status</option></term>
     <term><option>-s</option></term>
   
@@ -709,8 +890,8 @@ user environment elements, etc. -->
     
   </varlistentry>
 
-  <varlistentry><term><option>--attr</option></term>
-    <term><option>-a</option></term>
+  <varlistentry><term><option>--attr-path</option></term>
+    <term><option>-P</option></term>
 
     <listitem><para>Print the <emphasis>attribute path</emphasis> of
     the derivation, which can be used to unambiguously select it using
@@ -733,35 +914,35 @@ user environment elements, etc. -->
     <listitem><para>Compare installed versions to available versions,
     or vice versa (if <option>--available</option> is given).  This is
     useful for quickly seeing whether upgrades for installed
-    components are available in a Nix expression.  A column is added
+    packages are available in a Nix expression.  A column is added
     with the following meaning:
 
     <variablelist>
 
       <varlistentry><term><literal>&lt;</literal> <replaceable>version</replaceable></term>
 
-        <listitem><para>A newer version of the component is available
+        <listitem><para>A newer version of the package is available
         or installed.</para></listitem>
 
       </varlistentry>
       
       <varlistentry><term><literal>=</literal> <replaceable>version</replaceable></term>
 
-        <listitem><para>At most the same version of the component is
+        <listitem><para>At most the same version of the package is
         available or installed.</para></listitem>
 
       </varlistentry>
       
       <varlistentry><term><literal>></literal> <replaceable>version</replaceable></term>
 
-        <listitem><para>Only older versions of the component are
+        <listitem><para>Only older versions of the package are
         available or installed.</para></listitem>
 
       </varlistentry>
       
       <varlistentry><term><literal>- ?</literal></term>
 
-        <listitem><para>No version of the component is available or
+        <listitem><para>No version of the package is available or
         installed.</para></listitem>
 
       </varlistentry>
@@ -802,6 +983,14 @@ user environment elements, etc. -->
     
   </varlistentry>
 
+  <varlistentry><term><option>--meta</option></term>
+  
+    <listitem><para>Print all of the meta-attributes of the
+    derivation.  This option is only available with
+    <option>--xml</option>.</para></listitem>
+    
+  </varlistentry>
+
 </variablelist>
 
 </refsection>
@@ -1061,43 +1250,4 @@ error: no generation older than the current (91) exists</screen>
 
 
   
-<!--######################################################################-->
-
-<refsection><title>Operation <option>--import</option></title>
-
-<refsection><title>Synopsis</title>
-
-<cmdsynopsis>
-  <command>nix-env</command>
-  <group choice='req'>
-    <arg choice='plain'><option>--import</option></arg>
-    <arg choice='plain'><option>-I</option></arg>
-  </group>
-  <arg choice='req'><replaceable>path</replaceable></arg>
-</cmdsynopsis>
-
-</refsection>
-
-
-<refsection><title>Description</title>
-            
-<para>This operation makes <replaceable>path</replaceable> the default
-active Nix expression for the user.  That is, the symlink
-<filename>~/.nix-userenv</filename> is made to point to
-<replaceable>path</replaceable>.</para>
-
-</refsection>
-
-
-<refsection><title>Examples</title>
-
-<screen>
-$ nix-env -I ~/nixpkgs-0.5/</screen>
-
-</refsection>
-    
-</refsection>
-
-
-  
 </refentry>

doc/manual/nix-hash.xml

@@ -1,6 +1,14 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
+<refmeta>
+  <refentrytitle>nix-hash</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
+
 <refnamediv>
   <refname>nix-hash</refname>
   <refpurpose>compute the cryptographic hash of a path</refpurpose>

doc/manual/nix-install-package.xml

@@ -1,6 +1,14 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
+<refmeta>
+  <refentrytitle>nix-install-package</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
+
 <refnamediv>
   <refname>nix-install-package</refname>
   <refpurpose>install a Nix Package file</refpurpose>

doc/manual/nix-instantiate.xml

@@ -1,6 +1,14 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
+<refmeta>
+  <refentrytitle>nix-instantiate</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
+
 <refnamediv>
   <refname>nix-instantiate</refname>
   <refpurpose>instantiate store derivations from Nix expressions</refpurpose>
@@ -9,7 +17,7 @@
 <refsynopsisdiv>
   <cmdsynopsis>
     <command>nix-instantiate</command>
-    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xpointer(/nop/*)" />
+    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
     <arg><option>--arg</option> <replaceable>name</replaceable> <replaceable>value</replaceable></arg>
     <arg>
       <group choice='req'>

doc/manual/nix-pack-closure.xml

@@ -1,64 +0,0 @@
-<refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
-
-<refnamediv>
-  <refname>nix-pack-closure</refname>
-  <refpurpose>pack the closure of a store path into a single file that
-  can be unpacked with
-  <command>nix-unpack-closure</command></refpurpose>
-</refnamediv>
-
-<refsynopsisdiv>
-  <cmdsynopsis>
-    <command>nix-pack-closure</command>
-    <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg>
-  </cmdsynopsis>
-</refsynopsisdiv>
-
-
-<refsection><title>Description</title>
-
-<para>The command <command>nix-pack-closure</command> packs the
-contents of the store paths <replaceable>paths</replaceable> and
-<emphasis>all their dependencies</emphasis> into a single file, which
-is written to standard output.  (That is, it
-<emphasis>serialises</emphasis> <replaceable>paths</replaceable>.)
-The output can then be unpacked into the Nix store of another machine
-using <command>nix-unpack-closure</command>.</para>
-
-<para>Together, <command>nix-pack-closure</command> and
-<command>nix-unpack-closure</command> provide a quick and easy way to
-deploy a package to a different machine.  However, as the output of
-<command>nix-pack-closure</command> tends to be rather large (since it
-contains all dependencies), it’s not very efficient.
-<command>nix-push</command> and <command>nix-pull</command> are more
-efficient, but are also a bit more cumbersome to use.</para>
-
-</refsection>
-
-
-<refsection><title>Examples</title>
-
-<para>To copy some instance of Subversion with all its dependencies to
-another machine:
-
-<screen>
-$ nix-pack-closure /nix/store/hj232g1r...-subversion-1.3.0 > svn.closure
-
-<lineannotation>Copy <!-- !!! <filename> -->svn.closure to the remote machine, then on the remote machine do:</lineannotation>
-$ nix-unpack-closure &lt; svn.closure</screen>
-
-</para>
-
-<para>Copy the program <command>azureus</command> with all its
-dependencies to the machine <literal>scratchy</literal>:
-
-<screen>
-$ nix-pack-closure $(which azureus) | ssh scratchy nix-unpack-closure</screen>
-    
-</para>
-
-</refsection>
-
-
-</refentry>

doc/manual/nix-prefetch-url.xml

@@ -1,5 +1,14 @@
-<refentry>
+<refentry xmlns="http://docbook.org/ns/docbook"
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
   
+<refmeta>
+  <refentrytitle>nix-prefetch-url</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
+
 <refnamediv>
   <refname>nix-prefetch-url</refname>
   <refpurpose>copy a file from a URL into the store and print its MD5 hash</refpurpose>
@@ -38,7 +47,7 @@ avoided.</para>
 <para>The environment variable <envar>NIX_HASH_ALGO</envar> specifies
 which hash algorithm to use.  It can be either <literal>md5</literal>,
 <literal>sha1</literal>, or <literal>sha256</literal>.  The default is
-<literal>md5</literal>.</para>
+<literal>sha256</literal>.</para>
 
 <para>If <replaceable>hash</replaceable> is specified, then a download
 is not performed if the Nix store already contains a file with the

doc/manual/nix-pull.xml

@@ -1,5 +1,13 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+
+<refmeta>
+  <refentrytitle>nix-pull</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
 
 <refnamediv>
   <refname>nix-pull</refname>

doc/manual/nix-push.xml

@@ -1,5 +1,13 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+
+<refmeta>
+  <refentrytitle>nix-push</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
 
 <refnamediv>
   <refname>nix-push</refname>

doc/manual/nix-store.xml

@@ -1,5 +1,13 @@
 <refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+
+<refmeta>
+  <refentrytitle>nix-store</refentrytitle>
+  <manvolnum>1</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
 
 <refnamediv>
   <refname>nix-store</refname>
@@ -9,7 +17,7 @@
 <refsynopsisdiv>
   <cmdsynopsis>
     <command>nix-store</command>
-    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xpointer(/nop/*)" />
+    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="opt-common-syn.xml#xmlns(db=http://docbook.org/ns/docbook)xpointer(/db:nop/*)" />
     <arg><option>--add-root</option> <replaceable>path</replaceable></arg>
     <arg><option>--indirect</option></arg>
     <arg choice='plain'><replaceable>operation</replaceable></arg>
@@ -120,6 +128,7 @@ lrwxrwxrwx    1 ... 2005-03-13 21:10 /home/eelco/bla/result -> /nix/store/1r1134
     <arg choice='plain'><option>-r</option></arg>
   </group>
   <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg>
+  <arg><option>--dry-run</option></arg>
 </cmdsynopsis>
 
 </refsection>
@@ -158,6 +167,11 @@ the specified store paths.  Realisation is a somewhat overloaded term:
 output.  (For non-derivations argument, the argument itself is
 printed.)</para>
 
+<para>If the <option>--dry-run</option> option is used, then
+<command>nix-store</command> will print on standard error a
+description of what packages would be built or downloaded, and then
+quit.</para>
+
 </refsection>
             
 
@@ -196,6 +210,10 @@ linkend="sec-nix-build"><command>nix-build</command></link> does.</para>
     <arg choice='plain'><option>--print-dead</option></arg>
     <arg choice='plain'><option>--delete</option></arg>
   </group>
+  <arg><option>--max-freed</option> <replaceable>bytes</replaceable></arg>
+  <arg><option>--max-links</option> <replaceable>nrlinks</replaceable></arg>
+  <arg><option>--max-atime</option> <replaceable>atime</replaceable></arg>
+  <arg><option>--use-atime</option></arg>
 </cmdsynopsis>
 
 </refsection>
@@ -250,7 +268,70 @@ the Nix store not reachable via file system references from a set of
 
 </variablelist>
 
-<para>The behaviour of the collector is influenced by the <link
+<para>By default, all unreachable paths are deleted.  The following
+options control what gets deleted and in what order:
+
+<variablelist>
+
+  <varlistentry><term><option>--max-freed</option> <replaceable>bytes</replaceable></term>
+  
+    <listitem><para>Keep deleting paths until at least
+    <replaceable>bytes</replaceable> bytes have been
+    deleted, then stop.</para></listitem>
+    
+  </varlistentry>
+
+  <varlistentry><term><option>--max-links</option> <replaceable>nrlinks</replaceable></term>
+  
+    <listitem><para>Keep deleting paths until the hard link count on
+    <filename>/nix/store</filename> is less than
+    <replaceable>nrlinks</replaceable>, then stop.  This is useful for
+    very large Nix stores on filesystems with a 32000 subdirectories
+    limit (like <literal>ext3</literal>).</para></listitem>
+    
+  </varlistentry>
+
+  <varlistentry><term><option>--max-atime</option> <replaceable>atime</replaceable></term>
+  
+    <listitem><para>Only delete a store path if its last-accessed time
+    is less than <replaceable>atime</replaceable>.  This allows you to
+    garbage-collect only packages that haven’t been used recently.
+    The time is expressed as the number of seconds in the Unix epoch,
+    i.e., since 1970-01-01 00:00:00 UTC.  An easy way to convert to
+    this format is <literal>date +%s -d "<replaceable>date
+    specification</replaceable>"</literal>.</para>
+
+    <para>For directories, the last-accessed time is the highest
+    last-accessed time of any regular file in the directory (or in any
+    of its subdirectories).  That is, the <literal>atime</literal>
+    field maintained by the filesystem is ignored for directories.
+    This is because operations such as rebuilding the
+    <command>locate</command> database tend to update the
+    <literal>atime</literal> values of all directories, so they’re not
+    a useful indicator of whether a package was recently used.</para>
+
+    <para>Note that <command>nix-store --optimise</command> reads all
+    regular files in the Nix store, and so causes all last-accessed
+    times to be set to the present time.  This makes
+    <option>--max-atime</option> ineffective (for a while at
+    least).</para></listitem>
+    
+  </varlistentry>
+
+  <varlistentry><term><option>--use-atime</option></term>
+
+    <listitem><para>Delete store paths in order of ascending
+    last-accessed time.  This is useful in conjunction with the other
+    options to delete only the least recently used
+    packages.</para></listitem>
+
+  </varlistentry>
+  
+</variablelist>
+
+</para>
+
+<para>The behaviour of the collector is also influenced by the <link
 linkend="conf-gc-keep-outputs"><literal>gc-keep-outputs</literal></link>
 and <link
 linkend="conf-gc-keep-derivations"><literal>gc-keep-derivations</literal></link>
@@ -276,6 +357,20 @@ deleting `/nix/store/kq82idx6g0nyzsp2s14gfsc38npai7lf-cairo-1.0.4.tar.gz.drv'
 
 </para>
 
+<para>To delete unreachable paths not accessed in the last two months:
+
+<screen>
+$ nix-store --gc -v --max-atime $(date +%s -d "2 months ago")</screen>
+
+</para>
+
+<para>To delete at least 100 MiBs of unreachable paths:
+
+<screen>
+$ nix-store --gc --max-freed $((100 * 1024 * 1024))</screen>
+
+</para>
+
 </refsection>
 
 
@@ -651,37 +746,7 @@ $ gv graph.ps</screen>
 
 <!--######################################################################-->
 
-<!--
-<refsection><title>Operation <option>-XXX-substitute</option></title>
-
-<refsection><title>Synopsis</title>
-
-<cmdsynopsis>
-  <command>nix-store</command>
-  <arg choice='plain'><option>-XXX-substitute</option></arg>
-  <arg choice='plain'
-       rep='repeat'><replaceable>srcpath</replaceable> <replaceable>subpath</replaceable></arg>
-</cmdsynopsis>
-</refsection>
-
-<refsection><title>Description</title>
-            
-<para>The operation <option>-XXX-substitute</option> registers that the
-store path <replaceable>srcpath</replaceable> can be built by
-realising the derivation expression in
-<replaceable>subpath</replaceable>.  This is used to implement binary
-deployment.</para>
-
-</refsection>
-            
-</refsection>
--->
-
-
-
-<!--######################################################################-->
-
-<refsection><title>Operation <option>--verify</option></title>
+<refsection xml:id='refsec-nix-store-verify'><title>Operation <option>--verify</option></title>
 
 <refsection>
   <title>Synopsis</title>
@@ -801,4 +866,222 @@ archive is read from standard input.</para>
 </refsection>
 
 
+<!--######################################################################-->
+
+<refsection xml:id='refsec-nix-store-export'><title>Operation <option>--export</option></title>
+
+<refsection>
+  <title>Synopsis</title>
+  <cmdsynopsis>
+    <command>nix-store</command>
+    <arg choice='plain'><option>--export</option></arg>
+    <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg>
+  </cmdsynopsis>
+</refsection>
+
+<refsection><title>Description</title>
+            
+<para>The operation <option>--export</option> writes a serialisation
+of the specified store paths to standard output in a format that can
+be imported into another Nix store with <command
+linkend="refsec-nix-store-import">nix-store --import</command>.  This
+is like <command linkend="refsec-nix-store-dump">nix-store
+--dump</command>, except that the NAR archive produced by that command
+doesn’t contain the necessary meta-information to allow it to be
+imported into another Nix store (namely, the set of references of the
+path).</para>
+
+<para>This command does not produce a <emphasis>closure</emphasis> of
+the specified paths, so if a store path references other store paths
+that are missing in the target Nix store, the import will fail.  To
+copy a whole closure, do something like
+
+<screen>
+$ nix-store --export $(nix-store -qR <replaceable>paths</replaceable>) > out</screen>
+
+</para>
+
+<para>For an example of how <option>--export</option> and
+<option>--import</option> can be used, see the source of the <command
+linkend="sec-nix-copy-closure">nix-copy-closure</command>
+command.</para>
+
+</refsection>
+            
+
+</refsection>
+
+
+<!--######################################################################-->
+
+<refsection xml:id='refsec-nix-store-import'><title>Operation <option>--import</option></title>
+
+<refsection>
+  <title>Synopsis</title>
+  <cmdsynopsis>
+    <command>nix-store</command>
+    <arg choice='plain'><option>--import</option></arg>
+  </cmdsynopsis>
+</refsection>
+
+<refsection><title>Description</title>
+            
+<para>The operation <option>--export</option> reads a serialisation of
+a set of store paths produced by <command
+linkend="refsec-nix-store-export">nix-store --import</command> from
+standard input and adds those store paths to the Nix store.  Paths
+that already exist in the Nix store are ignored.  If a path refers to
+another path that doesn’t exist in the Nix store, the import
+fails.</para>
+
+</refsection>
+            
+
+</refsection>
+
+
+<!--######################################################################-->
+
+<refsection><title>Operation <option>--optimise</option></title>
+
+<refsection>
+  <title>Synopsis</title>
+  <cmdsynopsis>
+    <command>nix-store</command>
+    <arg choice='plain'><option>--optimise</option></arg>
+  </cmdsynopsis>
+</refsection>
+
+<refsection><title>Description</title>
+            
+<para>The operation <option>--optimise</option> reduces Nix store disk
+space usage by finding identical files in the store and hard-linking
+them to each other.  It typically reduces the size of the store by
+something like 25-35%.  Only regular files and symlinks are
+hard-linked in this manner.  Files are considered identical when they
+have the same NAR archive serialisation: that is, regular files must
+have the same contents and permission (executable or non-executable),
+and symlinks must have the same contents.</para>
+
+<para>After completion, or when the command is interrupted, a report
+on the achieved savings is printed on standard error.</para>
+
+<para>Use <option>-vv</option> or <option>-vvv</option> to get some
+progress indication.</para>
+
+</refsection>
+            
+<refsection><title>Example</title>
+
+<screen>
+$ nix-store --optimise
+hashing files in `/nix/store/qhqx7l2f1kmwihc9bnxs7rc159hsxnf3-gcc-4.1.1'
+<replaceable>...</replaceable>
+541838819 bytes (516.74 MiB) freed by hard-linking 54143 files;
+there are 114486 files with equal contents out of 215894 files in total
+</screen>
+
+</refsection>
+
+
+</refsection>
+
+
+<!--######################################################################-->
+
+<refsection><title>Operation <option>--read-log</option></title>
+
+<refsection>
+  <title>Synopsis</title>
+  <cmdsynopsis>
+    <command>nix-store</command>
+    <group choice='req'>
+      <arg choice='plain'><option>--read-log</option></arg>
+      <arg choice='plain'><option>-l</option></arg>
+    </group>
+    <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg>
+  </cmdsynopsis>
+</refsection>
+
+<refsection><title>Description</title>
+            
+<para>The operation <option>--read-log</option> prints the build log
+of the specified store paths on standard output.  The build log is
+whatever the builder of a derivation wrote to standard output and
+standard error.  If a store path is not a derivation, the deriver of
+the store path is used.</para>
+
+<para>Build logs are kept in
+<filename>/nix/var/log/nix/drvs</filename>.  However, there is no
+guarantee that a build log is available for any particular store
+path.  For instance, if the path was downloaded as a pre-built binary
+through a substitute, then the log is unavailable.</para>
+
+</refsection>
+            
+<refsection><title>Example</title>
+
+<screen>
+$ nix-store -l $(which ktorrent)
+building /nix/store/dhc73pvzpnzxhdgpimsd9sw39di66ph1-ktorrent-2.2.1
+unpacking sources
+unpacking source archive /nix/store/p8n1jpqs27mgkjw07pb5269717nzf5f8-ktorrent-2.2.1.tar.gz
+ktorrent-2.2.1/
+ktorrent-2.2.1/NEWS
+<replaceable>...</replaceable>
+</screen>
+
+</refsection>
+
+
+</refsection>
+
+
+<!--######################################################################-->
+
+<refsection><title>Operation <option>--dump-db</option></title>
+
+<refsection>
+  <title>Synopsis</title>
+  <cmdsynopsis>
+    <command>nix-store</command>
+    <arg choice='plain'><option>--dump-db</option></arg>
+  </cmdsynopsis>
+</refsection>
+
+<refsection><title>Description</title>
+            
+<para>The operation <option>--dump-db</option> writes a dump of the
+Nix database to standard output.  It can be loaded into an empty Nix
+store using <option>--load-db</option>.  This is useful for making
+backups and when migrating to different database schemas.</para>
+
+</refsection>
+            
+</refsection>
+
+
+<!--######################################################################-->
+
+<refsection><title>Operation <option>--dump-db</option></title>
+
+<refsection>
+  <title>Synopsis</title>
+  <cmdsynopsis>
+    <command>nix-store</command>
+    <arg choice='plain'><option>--load-db</option></arg>
+  </cmdsynopsis>
+</refsection>
+
+<refsection><title>Description</title>
+            
+<para>The operation <option>--load-db</option> reads a dump of the Nix
+database created by <option>--dump-db</option> from standard input and
+loads it into the Nix database.</para>
+
+</refsection>
+            
+</refsection>
+
+
 </refentry>

doc/manual/nix-unpack-closure.xml

@@ -1,28 +0,0 @@
-<refentry xmlns="http://docbook.org/ns/docbook"
-          xmlns:xlink="http://www.w3.org/1999/xlink">
-
-<refnamediv>
-  <refname>nix-unpack-closure</refname>
-  <refpurpose>unpack the closure of a store path created by <command>nix-pack-closure</command> into the Nix store</refpurpose>
-</refnamediv>
-
-<refsynopsisdiv>
-  <cmdsynopsis>
-    <command>nix-unpack-closure</command>
-  </cmdsynopsis>
-</refsynopsisdiv>
-
-
-<refsection><title>Description</title>
-
-<para>The command <command>nix-unpack-closure</command> unpacks the
-closure of a set of store paths created by
-<command>nix-pack-closure</command> into the local Nix store.  The
-closure is a single file read from standard input.  See the
-description of <command>nix-pack-closure</command> for details and
-examples.</para>
-
-</refsection>
-
-
-</refentry>

doc/manual/nix-worker.xml

@@ -0,0 +1,34 @@
+<refentry xmlns="http://docbook.org/ns/docbook"
+          xmlns:xlink="http://www.w3.org/1999/xlink"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+
+<refmeta>
+  <refentrytitle>nix-worker</refentrytitle>
+  <manvolnum>8</manvolnum>
+  <refmiscinfo class="source">Nix</refmiscinfo>
+  <refmiscinfo class="version"><xi:include href="version.txt" parse="text"/></refmiscinfo>
+</refmeta>
+
+<refnamediv>
+  <refname>nix-worker</refname>
+  <refpurpose>Nix multi-user support daemon</refpurpose>
+</refnamediv>
+
+<refsynopsisdiv>
+  <cmdsynopsis>
+    <command>nix-worker</command>
+    <arg choice="plain"><option>--daemon</option></arg>
+  </cmdsynopsis>
+</refsynopsisdiv>
+
+
+<refsection><title>Description</title>
+
+<para>The Nix daemon is necessary in multi-user Nix installations.  It
+performs build actions and other operations on the Nix store on behalf
+of unprivileged users.</para>
+
+
+</refsection>
+
+</refentry>

doc/manual/opt-common-syn.xml

@@ -1,4 +1,4 @@
-<nop>
+<nop xmlns="http://docbook.org/ns/docbook">
   
 <arg><option>--help</option></arg>
 <arg><option>--version</option></arg>
@@ -13,6 +13,10 @@
   </group>
   <replaceable>number</replaceable>
 </arg>
+<arg>
+  <arg><option>--max-silent-time</option></arg>
+  <replaceable>number</replaceable>
+</arg>
 <arg><option>--keep-going</option></arg>
 <arg><option>-k</option></arg>
 <arg><option>--keep-failed</option></arg>
@@ -20,6 +24,7 @@
 <arg><option>--fallback</option></arg>
 <arg><option>--readonly-mode</option></arg>
 <arg><option>--log-type</option> <replaceable>type</replaceable></arg>
+<arg><option>--show-trace</option></arg>
 <sbr />
 
 </nop>

doc/manual/opt-common.xml

@@ -103,6 +103,17 @@
 </varlistentry>
 
 
+<varlistentry xml:id="opt-max-silent-time"><term><option>--max-silent-time</option></term>
+
+  <listitem><para>Sets the maximum number of seconds that a builder
+  can go without producing any data on standard output or standard
+  error.  The default is specified by the <link
+  linkend='conf-build-max-silent-time'><literal>build-max-silent-time</literal></link>
+  configuration setting.  <literal>0</literal> means no
+  time-out.</para></listitem>
+
+</varlistentry>
+
 <varlistentry><term><option>--keep-going</option></term>
   <term><option>-k</option></term>
 
@@ -240,14 +251,14 @@
 
 <programlisting>
 { # The system (e.g., `i686-linux') for which to build the packages.
-  system ? __currentSystem
+  system ? builtins.currentSystem
   <replaceable>...</replaceable>
 }: <replaceable>...</replaceable></programlisting>
 
   So if you call this Nix expression (e.g., when you do
   <literal>nix-env -i <replaceable>pkgname</replaceable></literal>),
   the function will be called automatically using the value <link
-  linkend='builtin-currentSystem'><literal>__currentSystem</literal></link>
+  linkend='builtin-currentSystem'><literal>builtins.currentSystem</literal></link>
   for the <literal>system</literal> argument.  You can override this
   using <option>--arg</option>, e.g., <literal>nix-env -i
   <replaceable>pkgname</replaceable> --arg system
@@ -257,6 +268,17 @@
 </varlistentry>
 
 
+<varlistentry><term><option>--argstr</option> <replaceable>name</replaceable> <replaceable>value</replaceable></term>
+
+  <listitem><para>This option is like <option>--arg</option>, only the
+  value is not a Nix expression but a string.  So instead of
+  <literal>--arg system \"i686-linux\"</literal> (the outer quotes are
+  to keep the shell happy) you can say <literal>--argstr system
+  i686-linux</literal>.</para></listitem>
+
+</varlistentry>
+
+
 <varlistentry xml:id="opt-attr"><term><option>--attr</option> / <option>-A</option>
 <replaceable>attrPath</replaceable></term>
 
@@ -283,6 +305,14 @@
 </varlistentry>
 
 
+<varlistentry><term><option>--show-trace</option></term>
+  
+  <listitem><para>Causes Nix to print out a stack trace in case of Nix
+  expression evaluation errors.</para></listitem>
+  
+</varlistentry>
+
+
 </variablelist>
 
 

doc/manual/opt-inst-syn.xml

@@ -0,0 +1,22 @@
+<nop xmlns="http://docbook.org/ns/docbook">
+  
+  <arg>
+    <group choice='req'>
+      <arg choice='plain'><option>--prebuilt-only</option></arg>
+      <arg choice='plain'><option>-b</option></arg>
+    </group>
+  </arg>
+  
+  <arg>
+    <group choice='req'>
+      <arg choice='plain'><option>--attr</option></arg>
+      <arg choice='plain'><option>-A</option></arg>
+    </group>
+  </arg>
+
+  <arg><option>--from-expression</option></arg>
+  <arg><option>-E</option></arg>
+    
+  <arg><option>--from-profile</option> <replaceable>path</replaceable></arg>
+
+</nop>

doc/manual/package-management.xml

@@ -6,9 +6,9 @@
 
 
 <para>This chapter discusses how to do package management with Nix,
-i.e., how to obtain, install, upgrade, and erase components.  This is
+i.e., how to obtain, install, upgrade, and erase packages.  This is
 the “user’s” perspective of the Nix system — people
-who want to <emphasis>create</emphasis> components should consult
+who want to <emphasis>create</emphasis> packages should consult
 <xref linkend='chap-writing-nix-expressions' />.</para>
 
 
@@ -16,8 +16,8 @@ who want to <emphasis>create</emphasis> components should consult
 
 <para>The main command for package management is <link
 linkend="sec-nix-env"><command>nix-env</command></link>.  You can use
-it to install, upgrade, and erase components, and to query what
-components are installed or are available for installation.</para>
+it to install, upgrade, and erase packages, and to query what
+packages are installed or are available for installation.</para>
 
 <para>In Nix, different users can have different “views”
 on the set of installed applications.  That is, there might be lots of
@@ -30,18 +30,18 @@ environment</emphasis>, which is just a directory tree consisting of
 symlinks to the files of the active applications.  </para>
 
 <para>Components are installed from a set of <emphasis>Nix
-expressions</emphasis> that tell Nix how to build those components,
+expressions</emphasis> that tell Nix how to build those packages,
 including, if necessary, their dependencies.  There is a collection of
 Nix expressions called the Nix Package collection that contains
-components ranging from basic development stuff such as GCC and Glibc,
+packages ranging from basic development stuff such as GCC and Glibc,
 to end-user applications like Mozilla Firefox.  (Nix is however not
 tied to the Nix Package collection; you could write your own Nix
 expressions based on it, or completely new ones.)  You can download
 the latest version from <link
-xlink:href='http://nix.cs.uu.nl/dist/nix' />.</para>
+xlink:href='http://nixos.org/releases/full-index-nixpkgs.html' />.</para>
 
 <para>Assuming that you have downloaded and unpacked a release of Nix
-Packages, you can view the set of available components in the release:
+Packages, you can view the set of available packages in the release:
 
 <screen>
 $ nix-env -qaf nixpkgs-<replaceable>version</replaceable> '*'
@@ -74,7 +74,7 @@ gcc-4.1.1</screen>
 </para>
 
 <para>It is also possible to see the <emphasis>status</emphasis> of
-available components, i.e., whether they are installed into the user
+available packages, i.e., whether they are installed into the user
 environment and/or present in the system:
 
 <screen>
@@ -86,24 +86,24 @@ IPS bison-1.875d
 ...</screen>
 
 The first character (<literal>I</literal>) indicates whether the
-component is installed in your current user environment.  The second
+package is installed in your current user environment.  The second
 (<literal>P</literal>) indicates whether it is present on your system
 (in which case installing it into your user environment would be a
 very quick operation).  The last one (<literal>S</literal>) indicates
 whether there is a so-called <emphasis>substitute</emphasis> for the
-component, which is Nix’s mechanism for doing binary deployment.  It
-just means that Nix know that it can fetch a pre-built component from
+package, which is Nix’s mechanism for doing binary deployment.  It
+just means that Nix knows that it can fetch a pre-built package from
 somewhere (typically a network server) instead of building it
 locally.</para>
 
 <para>So now that we have a set of Nix expressions we can build the
-components contained in them.  This is done using <literal>nix-env
+packages contained in them.  This is done using <literal>nix-env
 -i</literal>.  For instance,
 
 <screen>
 $ nix-env -f nixpkgs-<replaceable>version</replaceable> -i subversion</screen>
 
-will install the component called <literal>subversion</literal> (which
+will install the package called <literal>subversion</literal> (which
 is, of course, the <link
 xlink:href='http://subversion.tigris.org/'>Subversion version
 management system</link>).</para>
@@ -112,21 +112,21 @@ management system</link>).</para>
 Subversion and all its dependencies.  This will take quite a while —
 typically an hour or two on modern machines.  Fortunately, there is a
 faster way (so do a Ctrl-C on that install operation!): you just need
-to tell Nix that pre-built binaries of all those components are
+to tell Nix that pre-built binaries of all those packages are
 available somewhere.  This is done using the
 <command>nix-pull</command> command, which must be supplied with a URL
 containing a <emphasis>manifest</emphasis> describing what binaries
 are available.  This URL should correspond to the Nix Packages release
 that you’re using.  For instance, if you obtained a release from <link
-xlink:href='http://nix.cs.uu.nl/dist/nix/nixpkgs-0.6pre1554/' />, then
-you should do:
+xlink:href='http://nixos.org/releases/nixpkgs/nixpkgs-0.12pre11712-4lrp7j8x'
+/>, then you should do:
 
 <screen>
-$ nix-pull http://nix.cs.uu.nl/dist/nix/nixpkgs-0.6pre1554/MANIFEST</screen>
+$ nix-pull http://nixos.org/releases/nixpkgs/nixpkgs-0.12pre11712-4lrp7j8x/MANIFEST</screen>
 
 If you then issue the installation command, it should start
 downloading binaries from <systemitem
-class='fqdomainname'>nix.cs.uu.nl</systemitem>, instead of building
+class='fqdomainname'>nixos.org</systemitem>, instead of building
 them from source.  This might still take a while since all
 dependencies must be downloaded, but on a reasonably fast connection
 such as an DSL line it’s on the order of a few minutes.</para>
@@ -153,7 +153,7 @@ expressions, use <parameter>-i</parameter> instead of
 <parameter>-u</parameter>; <parameter>-i</parameter> will remove
 whatever version is already installed.</para>
 
-<para>You can also upgrade all components for which there are newer
+<para>You can also upgrade all packages for which there are newer
 versions:
 
 <screen>
@@ -199,19 +199,19 @@ set.</para></footnote></para>
 implementing the ability to allow different users to have different
 configurations, and to do atomic upgrades and rollbacks.  To
 understand how they work, it’s useful to know a bit about how Nix
-works.  In Nix, components are stored in unique locations in the
+works.  In Nix, packages are stored in unique locations in the
 <emphasis>Nix store</emphasis> (typically,
 <filename>/nix/store</filename>).  For instance, a particular version
-of the Subversion component might be stored in a directory
+of the Subversion package might be stored in a directory
 <filename>/nix/store/dpmvp969yhdqs7lm2r1a3gng7pyq6vy4-subversion-1.1.3/</filename>,
 while another version might be stored in
 <filename>/nix/store/5mq2jcn36ldlmh93yj1n8s9c95pj7c5s-subversion-1.1.2</filename>.
 The long strings prefixed to the directory names are cryptographic
 hashes<footnote><para>160-bit truncations of SHA-256 hashes encoded in
 a base-32 notation, to be precise.</para></footnote> of
-<emphasis>all</emphasis> inputs involved in building the component —
+<emphasis>all</emphasis> inputs involved in building the package —
 sources, dependencies, compiler flags, and so on.  So if two
-components differ in any way, they end up in different locations in
+packages differ in any way, they end up in different locations in
 the file system, so they don’t interfere with each other.  <xref
 linkend='fig-user-environments' /> shows a part of a typical Nix
 store.</para>
@@ -231,12 +231,12 @@ $ /nix/store/dpmvp969yhdq...-subversion-1.1.3/bin/svn</screen>
 
 every time you want to run Subversion.  Of course we could set up the
 <envar>PATH</envar> environment variable to include the
-<filename>bin</filename> directory of every component we want to use,
+<filename>bin</filename> directory of every package we want to use,
 but this is not very convenient since changing <envar>PATH</envar>
 doesn’t take effect for already existing processes.  The solution Nix
 uses is to create directory trees of symlinks to
-<emphasis>activated</emphasis> components.  These are called
-<emphasis>user environments</emphasis> and they are components
+<emphasis>activated</emphasis> packages.  These are called
+<emphasis>user environments</emphasis> and they are packages
 themselves (though automatically generated by
 <command>nix-env</command>), so they too reside in the Nix store.  For
 instance, in <xref linkend='fig-user-environments' /> the user
@@ -285,8 +285,8 @@ operation, a new user environment and generation link are created
 based on the current one, and finally the <filename>default</filename>
 symlink is made to point at the new generation.  This last step is
 atomic on Unix, which explains how we can do atomic upgrades.  (Note
-that the building/installing of new components doesn’t interfere in
-any way with old components, since they are stored in different
+that the building/installing of new packages doesn’t interfere in
+any way with old packages, since they are stored in different
 locations in the Nix store.)</para>
 
 <para>If you find that you want to undo a <command>nix-env</command>
@@ -352,18 +352,18 @@ This will <emphasis>not</emphasis> change the
 
 <para><command>nix-env</command> operations such as upgrades
 (<option>-u</option>) and uninstall (<option>-e</option>) never
-actually delete components from the system.  All they do (as shown
+actually delete packages from the system.  All they do (as shown
 above) is to create a new user environment that no longer contains
-symlinks to the “deleted” components.</para>
+symlinks to the “deleted” packages.</para>
 
-<para>Of course, since disk space is not infinite, unused components
+<para>Of course, since disk space is not infinite, unused packages
 should be removed at some point.  You can do this by running the Nix
-garbage collector.  It will remove from the Nix store any component
+garbage collector.  It will remove from the Nix store any package
 not used (directly or indirectly) by any generation of any
 profile.</para>
 
 <para>Note however that as long as old generations reference a
-component, it will not be deleted.  After all, we wouldn’t be able to
+package, it will not be deleted.  After all, we wouldn’t be able to
 do a rollback otherwise.  So in order for garbage collection to be
 effective, you should also delete (some) old generations.  Of course,
 this should only be done if you are certain that you will not need to
@@ -458,7 +458,7 @@ URL.</para>
 <command>nix-channel --add</command>, e.g.,
 
 <screen>
-$ nix-channel --add http://nix.cs.uu.nl/dist/nix/channels-v3/nixpkgs-unstable</screen>
+$ nix-channel --add http://nixos.org/releases/nixpkgs/channels/nixpkgs-unstable</screen>
 
 subscribes you to a channel that always contains that latest version
 of the Nix Packages collection.  (Instead of
@@ -486,7 +486,7 @@ makes the union of each channel’s Nix expressions the default for
 <screen>
 $ nix-env -u '*'</screen>
 
-to upgrade all components in your profile to the latest versions
+to upgrade all packages in your profile to the latest versions
 available in the subscribed channels.</para>
 
 </section>
@@ -496,20 +496,19 @@ available in the subscribed channels.</para>
 
 <para>Often, when you want to install a specific package (e.g., from
 the <link
-xlink:href="http://nix.cs.uu.nl/dist/nix/nixpkgs-unstable-latest/">Nix
-Packages collection</link> or from our <link
-xlink:href='http://nix.cs.uu.nl/dist/'>release server</link>),
-subscribing to a channel is a bit cumbersome.  And channels don’t help
-you at all if you want to install an older version of a package than
-the one provided by the current contents of the channel, or a package
-that has been removed from the channel.  That’s when
-<emphasis>one-click installs</emphasis> come in handy: you can just go
-to the web page that contains the package, click on it, and it will be
-installed with all the necessary dependencies.</para>
+xlink:href="http://nixos.org/releases/nixpkgs/nixpkgs-unstable/">Nix
+Packages collection</link>), subscribing to a channel is a bit
+cumbersome.  And channels don’t help you at all if you want to install
+an older version of a package than the one provided by the current
+contents of the channel, or a package that has been removed from the
+channel.  That’s when <emphasis>one-click installs</emphasis> come in
+handy: you can just go to the web page that contains the package,
+click on it, and it will be installed with all the necessary
+dependencies.</para>
 
 <para>For instance, you can go to <link
-xlink:href="http://nix.cs.uu.nl/dist/nix/nixpkgs-unstable-latest/" />
-— or to any older release of Nix Packages — and click on any link for
+xlink:href="http://nixos.org/releases/nixpkgs/nixpkgs-unstable/" /> —
+or to any older release of Nix Packages — and click on any link for
 the individual packages for your platform (say, <link
 xlink:href='http://nix.cs.uu.nl/dist/nix/nixpkgs-0.10pre6622/pkgs/subversion-1.4.0-i686-linux.nixpkg'><literal>subversion-1.4.0</literal>
 for <literal>i686-linux</literal></link>).  The first time you do
@@ -529,4 +528,82 @@ linkend='sec-nix-install-package' /> for details.</para>
 </section>
 
 
+<section xml:id="sec-sharing-packages"><title>Sharing packages between machines</title>
+
+<para>Sometimes you want to copy a package from one machine to
+another.  Or, you want to install some packages and you know that
+another machine already has some or all of those packages or their
+dependencies.  In that case there are mechanisms to quickly copy
+packages between machines.</para>
+
+<para>The command <command
+linkend="sec-nix-copy-closure">nix-copy-closure</command> copies a Nix
+store path along with all its dependencies to or from another machine
+via the SSH protocol.  It doesn’t copy store paths that are already
+present on the target machine.  For example, the following command
+copies Firefox with all its dependencies:
+
+<screen>
+$ nix-copy-closure --to alice@itchy.example.org $(type -p firefox)</screen>
+
+See <xref linkend='sec-nix-copy-closure' /> for details.</para>
+
+<para>With <command linkend='refsec-nix-store-export'>nix-store
+--export</command> and <command
+linkend='refsec-nix-store-import'>nix-store --import</command> you can
+write the closure of a store path (that is, the path and all its
+dependencies) to a file, and then unpack that file into another Nix
+store.  For example,
+
+<screen>
+$ nix-store --export $(type -p firefox) > firefox.closure</screen>
+
+writes the closure of Firefox to a file.  You can then copy this file
+to another machine and install the closure:
+
+<screen>
+$ nix-store --import &lt; firefox.closure</screen>
+
+Any store paths in the closure that are already present in the target
+store are ignored.  It is also possible to pipe the export into
+another command, e.g. to copy and install a closure directly to/on
+another machine:
+
+<screen>
+$ nix-store --export $(type -p firefox) | bzip2 | \
+    ssh alice@itchy.example.org "bunzip2 | nix-store --import"</screen>
+
+But note that <command>nix-copy-closure</command> is generally more
+efficient in this example because it only copies paths that are not
+already present in the target Nix store.</para>
+
+<para>Finally, if you can mount the Nix store of a remote machine in
+your local filesystem, Nix can copy paths from the remote Nix store to
+the local Nix store <emphasis>on demand</emphasis>.  For instance,
+suppose that you mount a remote machine containing a Nix store via
+<command
+xlink:href="http://fuse.sourceforge.net/sshfs.html">sshfs</command>:
+
+<screen>
+$ sshfs alice@itchy.example.org:/ /mnt</screen>
+
+You should then set the <envar>NIX_OTHER_STORES</envar> environment
+variable to tell Nix about this remote Nix store:
+
+<screen>
+$ export NIX_OTHER_STORES=/mnt/nix</screen>
+
+Then if you do any Nix operation, e.g.
+
+<screen>
+$ nix-env -i firefox</screen>
+
+and Nix has to build a path that it sees is already present in
+<filename>/mnt/nix</filename>, then it will just copy from there
+instead of building it from source.</para>
+ 
+
+</section>
+
+
 </chapter>

doc/manual/quick-start.xml

@@ -11,7 +11,7 @@ to the following chapters.</para>
 <orderedlist>
 
 <listitem><para>Download a source tarball or RPM from <link
-xlink:href='http://www.cs.uu.nl/groups/ST/Trace/Nix'/>.  Build source
+xlink:href='http://nixos.org/'/>.  Build source
 distributions using the regular sequence:
         
 <screen>
@@ -22,8 +22,9 @@ $ make install <lineannotation>(as root)</lineannotation></screen>
 
 This will install Nix in <filename>/nix</filename>.  You shouldn't
 change the prefix if at all possible since that will make it
-impossible to use our pre-built components.  Alternatively, you could
-grab an RPM if you're on an RPM-based system.  You should also add
+impossible to use pre-built binaries from the Nixpkgs channel and
+other channels.  Alternatively, you could grab an RPM if you're on an
+RPM-based system.  You should also add
 <filename>/nix/etc/profile.d/nix.sh</filename> to your
 <filename>~/.bashrc</filename> (or some other login
 file).</para></listitem>
@@ -32,7 +33,7 @@ file).</para></listitem>
 
 <screen>
 $ nix-channel --add \
-    http://nix.cs.uu.nl/dist/nix/channels-v3/nixpkgs-unstable</screen>
+    http://nixos.org/releases/nixpkgs/channels/nixpkgs-unstable</screen>
 
 </para></listitem>
 
@@ -40,14 +41,14 @@ $ nix-channel --add \
 <screen>
 $ nix-channel --update</screen>
 
-Note that this in itself doesn't download any components, it just
+Note that this in itself doesn't download any packages, it just
 downloads the Nix expressions that build them and stores them
 somewhere (under <filename>~/.nix-defexpr</filename>, in case you're
 curious).  Also, it registers the fact that pre-built binaries are
 available remotely.</para></listitem>
 
-<listitem><para>See what installable components are currently
-available in the channel:
+<listitem><para>See what installable packages are currently available
+in the channel:
 
 <screen>
 $ nix-env -qa ’*’ <lineannotation>(mind the quotes!)</lineannotation>
@@ -59,13 +60,13 @@ libxslt-1.1.0
 
 </para></listitem>
 
-<listitem><para>Install some components from the channel:
+<listitem><para>Install some packages from the channel:
         
 <screen>
 $ nix-env -i hello firefox <replaceable>...</replaceable> </screen>
 
-This should download the pre-built components; it should not build
-them locally (if it does, something went wrong).</para></listitem>
+This should download pre-built packages; it should not build them
+locally (if it does, something went wrong).</para></listitem>
 
 <listitem><para>Test that they work:
 
@@ -92,8 +93,8 @@ $ nix-env -e hello</screen>
 $ nix-channel --update
 $ nix-env -u '*'</screen>
 
-The latter command will upgrade each installed component for which
-there is a “newer” version (as determined by comparing the version
+The latter command will upgrade each installed package for which there
+is a “newer” version (as determined by comparing the version
 numbers).</para></listitem>
 
 <listitem><para>You can also install specific packages directly from
@@ -107,7 +108,7 @@ appear asking you whether it’s okay to install the package.  Say
 installed.</para></listitem>
 
 <listitem><para>If you're unhappy with the result of a
-<command>nix-env</command> action (e.g., an upgraded component turned
+<command>nix-env</command> action (e.g., an upgraded package turned
 out not to work properly), you can go back:
 
 <screen>
@@ -124,7 +125,7 @@ $ nix-collect-garbage -d</screen>
 
 <!--
 The first command deletes old “generations” of your profile (making
-rollbacks impossible, but also making the components in those old
+rollbacks impossible, but also making the packages in those old
 generations available for garbage collection), while the second
 command actually deletes them.-->
 

doc/manual/release-notes.xml

@@ -1,10 +1,545 @@
 <article xmlns="http://docbook.org/ns/docbook"
-         xmlns:xlink="http://www.w3.org/1999/xlink">
+         xmlns:xlink="http://www.w3.org/1999/xlink"
+         xml:id="sec-relnotes">
 
 <title>Nix Release Notes</title>
 
 
 
+<!--==================================================================-->
+
+<section xml:id="ssec-relnotes-0.13"><title>Release 0.13 (April NN,
+2009)</title>
+
+<para>This is primarily a bug fix release.  It has some new
+features:</para>
+
+<itemizedlist>
+
+  <listitem>
+    <para>Syntactic sugar for writing nested attribute sets.  Instead of
+
+<programlisting>
+{
+  foo = {
+    bar = 123;
+    xyzzy = true;
+  };
+  a = { b = { c = "d"; }; };
+}
+</programlisting>
+
+    you can write
+
+<programlisting>
+{
+  foo.bar = 123;
+  foo.xyzzy = true;
+  a.b.c = "d";
+}
+</programlisting>
+
+    This is useful, for instance, in NixOS configuration files.</para>
+    
+  </listitem>
+
+  <listitem>
+    <para>Support for Nix channels generated by Hydra, the Nix-based
+    continuous build system.  (Hydra generates NAR archives on the
+    fly, so the size and hash of these archives isn’t known in
+    advance.)</para>
+  </listitem>
+
+  <listitem>
+    <para>Support <literal>i686-linux</literal> builds directly on
+    <literal>x86_64-linux</literal> Nix installations.  This is
+    implemented using the <function>personality()</function> syscall,
+    which causes <command>uname</command> to return
+    <literal>i686</literal> in child processes.</para>
+  </listitem>
+  
+  <listitem>
+    <para>Various improvements to the <literal>chroot</literal>
+    support.  Building in a <literal>chroot</literal> works quite well
+    now.</para>
+  </listitem>
+
+  <listitem>
+    <para>Nix no longer blocks if it tries to build a path and another
+    process is already building the same path.  Instead it tries to
+    build another buildable path first.  This improves
+    parallelism.</para>
+  </listitem>
+
+  <listitem>
+    <para>Support for large (> 4 GiB) files in NAR archives.</para>
+  </listitem>
+    
+  <listitem>
+    <para>Various (performance) improvements to the remote build
+    mechanism.</para>
+  </listitem>
+    
+  <listitem>
+    <para>New primops: <varname>builtins.addErrorContext</varname> (to
+    add a string to stack traces — useful for debugging),
+    <varname>builtins.isBool</varname>,
+    <varname>builtins.isString</varname>,
+    <varname>builtins.isInt</varname>.</para>
+  </listitem>
+
+</itemizedlist>
+
+</section>
+
+
+<!--==================================================================-->
+
+<section xml:id="ssec-relnotes-0.12"><title>Release 0.12 (November 20,
+2008)</title>
+
+<itemizedlist>
+
+  <listitem>
+    <para>Nix no longer uses Berkeley DB to store Nix store metadata.
+    The principal advantages of the new storage scheme are: it works
+    properly over decent implementations of NFS (allowing Nix stores
+    to be shared between multiple machines); no recovery is needed
+    when a Nix process crashes; no write access is needed for
+    read-only operations; no more running out of Berkeley DB locks on
+    certain operations.</para>
+
+    <para>You still need to compile Nix with Berkeley DB support if
+    you want Nix to automatically convert your old Nix store to the
+    new schema.  If you don’t need this, you can build Nix with the
+    <filename>configure</filename> option
+    <option>--disable-old-db-compat</option>.</para>
+
+    <para>After the automatic conversion to the new schema, you can
+    delete the old Berkeley DB files:
+
+    <screen>
+$ cd /nix/var/nix/db
+$ rm __db* log.* derivers references referrers reserved validpaths DB_CONFIG</screen>
+
+    The new metadata is stored in the directories
+    <filename>/nix/var/nix/db/info</filename> and
+    <filename>/nix/var/nix/db/referrer</filename>.  Though the
+    metadata is stored in human-readable plain-text files, they are
+    not intended to be human-editable, as Nix is rather strict about
+    the format.</para>
+
+    <para>The new storage schema may or may not require less disk
+    space than the Berkeley DB environment, mostly depending on the
+    cluster size of your file system.  With 1 KiB clusters (which
+    seems to be the <literal>ext3</literal> default nowadays) it
+    usually takes up much less space.</para>
+  </listitem>
+
+  <listitem><para>There is a new substituter that copies paths
+  directly from other (remote) Nix stores mounted somewhere in the
+  filesystem.  For instance, you can speed up an installation by
+  mounting some remote Nix store that already has the packages in
+  question via NFS or <literal>sshfs</literal>.  The environment
+  variable <envar>NIX_OTHER_STORES</envar> specifies the locations of
+  the remote Nix directories,
+  e.g. <literal>/mnt/remote-fs/nix</literal>.</para></listitem>
+
+  <listitem><para>New <command>nix-store</command> operations
+  <option>--dump-db</option> and <option>--load-db</option> to dump
+  and reload the Nix database.</para></listitem>
+
+  <listitem><para>The garbage collector has a number of new options to
+  allow only some of the garbage to be deleted.  The option
+  <option>--max-freed <replaceable>N</replaceable></option> tells the
+  collector to stop after at least <replaceable>N</replaceable> bytes
+  have been deleted.  The option <option>--max-links
+  <replaceable>N</replaceable></option> tells it to stop after the
+  link count on <filename>/nix/store</filename> has dropped below
+  <replaceable>N</replaceable>.  This is useful for very large Nix
+  stores on filesystems with a 32000 subdirectories limit (like
+  <literal>ext3</literal>).  The option <option>--use-atime</option>
+  causes store paths to be deleted in order of ascending last access
+  time.  This allows non-recently used stuff to be deleted.  The
+  option <option>--max-atime <replaceable>time</replaceable></option>
+  specifies an upper limit to the last accessed time of paths that may
+  be deleted.  For instance,
+
+    <screen>
+    $ nix-store --gc -v --max-atime $(date +%s -d "2 months ago")</screen>
+
+  deletes everything that hasn’t been accessed in two months.</para></listitem>
+
+  <listitem><para><command>nix-env</command> now uses optimistic
+  profile locking when performing an operation like installing or
+  upgrading, instead of setting an exclusive lock on the profile.
+  This allows multiple <command>nix-env -i / -u / -e</command>
+  operations on the same profile in parallel.  If a
+  <command>nix-env</command> operation sees at the end that the profile
+  was changed in the meantime by another process, it will just
+  restart.  This is generally cheap because the build results are
+  still in the Nix store.</para></listitem>
+
+  <listitem><para>The option <option>--dry-run</option> is now
+  supported by <command>nix-store -r</command> and
+  <command>nix-build</command>.</para></listitem>
+
+  <listitem><para>The information previously shown by
+  <option>--dry-run</option> (i.e., which derivations will be built
+  and which paths will be substituted) is now always shown by
+  <command>nix-env</command>, <command>nix-store -r</command> and
+  <command>nix-build</command>.  The total download size of
+  substitutable paths is now also shown.  For instance, a build will
+  show something like
+
+    <screen>
+the following derivations will be built:
+  /nix/store/129sbxnk5n466zg6r1qmq1xjv9zymyy7-activate-configuration.sh.drv
+  /nix/store/7mzy971rdm8l566ch8hgxaf89x7lr7ik-upstart-jobs.drv
+  ...
+the following paths will be downloaded/copied (30.02 MiB):
+  /nix/store/4m8pvgy2dcjgppf5b4cj5l6wyshjhalj-samba-3.2.4
+  /nix/store/7h1kwcj29ip8vk26rhmx6bfjraxp0g4l-libunwind-0.98.6
+  ...</screen>      
+  
+  </para></listitem>
+
+  <listitem><para>Language features:
+
+    <itemizedlist>
+
+      <listitem><para>@-patterns as in Haskell.  For instance, in a
+      function definition
+
+      <programlisting>f = args @ {x, y, z}: <replaceable>...</replaceable>;</programlisting>
+
+      <varname>args</varname> refers to the argument as a whole, which
+      is further pattern-matched against the attribute set pattern
+      <literal>{x, y, z}</literal>.</para></listitem>
+
+      <listitem><para>“<literal>...</literal>” (ellipsis) patterns.
+      An attribute set pattern can now say <literal>...</literal>  at
+      the end of the attribute name list to specify that the function
+      takes <emphasis>at least</emphasis> the listed attributes, while
+      ignoring additional attributes.  For instance,
+
+      <programlisting>{stdenv, fetchurl, fuse, ...}: <replaceable>...</replaceable></programlisting>
+
+      defines a function that accepts any attribute set that includes
+      at least the three listed attributes.</para></listitem>
+
+      <listitem><para>New primops:
+      <varname>builtins.parseDrvName</varname> (split a package name
+      string like <literal>"nix-0.12pre12876"</literal> into its name
+      and version components, e.g. <literal>"nix"</literal> and
+      <literal>"0.12pre12876"</literal>),
+      <varname>builtins.compareVersions</varname> (compare two version
+      strings using the same algorithm that <command>nix-env</command>
+      uses), <varname>builtins.length</varname> (efficiently compute
+      the length of a list), <varname>builtins.mul</varname> (integer
+      multiplication), <varname>builtins.div</varname> (integer
+      division).
+      <!-- <varname>builtins.genericClosure</varname> -->
+      </para></listitem>
+      
+    </itemizedlist>
+
+  </para></listitem>
+
+  <listitem><para><command>nix-prefetch-url</command> now supports
+  <literal>mirror://</literal> URLs, provided that the environment
+  variable <envar>NIXPKGS_ALL</envar> points at a Nixpkgs
+  tree.</para></listitem>
+
+  <listitem><para>Removed the commands
+  <command>nix-pack-closure</command> and
+  <command>nix-unpack-closure</command>.   You can do almost the same
+  thing but much more efficiently by doing <literal>nix-store --export
+  $(nix-store -qR <replaceable>paths</replaceable>) > closure</literal> and
+  <literal>nix-store --import &lt;
+  closure</literal>.</para></listitem>
+
+  <listitem><para>Lots of bug fixes, including a big performance bug in
+  the handling of <literal>with</literal>-expressions.</para></listitem>
+
+</itemizedlist>
+
+</section>
+
+
+<!--==================================================================-->
+
+<section xml:id="ssec-relnotes-0.11"><title>Release 0.11 (December 31,
+2007)</title>
+
+<para>Nix 0.11 has many improvements over the previous stable release.
+The most important improvement is secure multi-user support.  It also
+features many usability enhancements and language extensions, many of
+them prompted by NixOS, the purely functional Linux distribution based
+on Nix.  Here is an (incomplete) list:</para>
+
+
+<itemizedlist>
+
+
+  <listitem><para>Secure multi-user support.  A single Nix store can
+  now be shared between multiple (possible untrusted) users.  This is
+  an important feature for NixOS, where it allows non-root users to
+  install software.  The old setuid method for sharing a store between
+  multiple users has been removed.  Details for setting up a
+  multi-user store can be found in the manual.</para></listitem>
+
+
+  <listitem><para>The new command <command>nix-copy-closure</command>
+  gives you an easy and efficient way to exchange software between
+  machines.  It copies the missing parts of the closure of a set of
+  store path to or from a remote machine via
+  <command>ssh</command>.</para></listitem>
+
+
+  <listitem><para>A new kind of string literal: strings between double
+  single-quotes (<literal>''</literal>) have indentation
+  “intelligently” removed.  This allows large strings (such as shell
+  scripts or configuration file fragments in NixOS) to cleanly follow
+  the indentation of the surrounding expression.  It also requires
+  much less escaping, since <literal>''</literal> is less common in
+  most languages than <literal>"</literal>.</para></listitem>
+
+
+  <listitem><para><command>nix-env</command> <option>--set</option>
+  modifies the current generation of a profile so that it contains
+  exactly the specified derivation, and nothing else.  For example,
+  <literal>nix-env -p /nix/var/nix/profiles/browser --set
+  firefox</literal> lets the profile named
+  <filename>browser</filename> contain just Firefox.</para></listitem>
+  
+
+  <listitem><para><command>nix-env</command> now maintains
+  meta-information about installed packages in profiles.  The
+  meta-information is the contents of the <varname>meta</varname>
+  attribute of derivations, such as <varname>description</varname> or
+  <varname>homepage</varname>.  The command <literal>nix-env -q --xml
+  --meta</literal> shows all meta-information.</para></listitem>
+
+  
+  <listitem><para><command>nix-env</command> now uses the
+  <varname>meta.priority</varname> attribute of derivations to resolve
+  filename collisions between packages.  Lower priority values denote
+  a higher priority.  For instance, the GCC wrapper package and the
+  Binutils package in Nixpkgs both have a file
+  <filename>bin/ld</filename>, so previously if you tried to install
+  both you would get a collision.  Now, on the other hand, the GCC
+  wrapper declares a higher priority than Binutils, so the former’s
+  <filename>bin/ld</filename> is symlinked in the user
+  environment.</para></listitem>
+
+
+  <listitem><para><command>nix-env -i / -u</command>: instead of
+  breaking package ties by version, break them by priority and version
+  number.  That is, if there are multiple packages with the same name,
+  then pick the package with the highest priority, and only use the
+  version if there are multiple packages with the same
+  priority.</para>
+
+  <para>This makes it possible to mark specific versions/variant in
+  Nixpkgs more or less desirable than others.  A typical example would
+  be a beta version of some package (e.g.,
+  <literal>gcc-4.2.0rc1</literal>) which should not be installed even
+  though it is the highest version, except when it is explicitly
+  selected (e.g., <literal>nix-env -i
+  gcc-4.2.0rc1</literal>).</para></listitem>
+
+
+  <listitem><para><command>nix-env --set-flag</command> allows meta
+  attributes of installed packages to be modified.  There are several
+  attributes that can be usefully modified, because they affect the
+  behaviour of <command>nix-env</command> or the user environment
+  build script:
+
+    <itemizedlist>
+
+      <listitem><para><varname>meta.priority</varname> can be changed
+      to resolve filename clashes (see above).</para></listitem>
+
+      <listitem><para><varname>meta.keep</varname> can be set to
+      <literal>true</literal> to prevent the package from being
+      upgraded or replaced.  Useful if you want to hang on to an older
+      version of a package.</para></listitem>
+
+      <listitem><para><varname>meta.active</varname> can be set to
+      <literal>false</literal> to “disable” the package.  That is, no
+      symlinks will be generated to the files of the package, but it
+      remains part of the profile (so it won’t be garbage-collected).
+      Set it back to <literal>true</literal> to re-enable the
+      package.</para></listitem>
+
+    </itemizedlist>
+
+  </para></listitem>
+
+  
+  <listitem><para><command>nix-env -q</command> now has a flag
+  <option>--prebuilt-only</option> (<option>-b</option>) that causes
+  <command>nix-env</command> to show only those derivations whose
+  output is already in the Nix store or that can be substituted (i.e.,
+  downloaded from somewhere).  In other words, it shows the packages
+  that can be installed “quickly”, i.e., don’t need to be built from
+  source.  The <option>-b</option> flag is also available in
+  <command>nix-env -i</command> and <command>nix-env -u</command> to
+  filter out derivations for which no pre-built binary is
+  available.</para></listitem>
+  
+
+  <listitem><para>The new option <option>--argstr</option> (in
+  <command>nix-env</command>, <command>nix-instantiate</command> and
+  <command>nix-build</command>) is like <option>--arg</option>, except
+  that the value is a string.  For example, <literal>--argstr system
+  i686-linux</literal> is equivalent to <literal>--arg system
+  \"i686-linux\"</literal> (note that <option>--argstr</option>
+  prevents annoying quoting around shell arguments).</para></listitem>
+
+
+  <listitem><para><command>nix-store</command> has a new operation
+  <option>--read-log</option> (<option>-l</option>)
+  <parameter>paths</parameter> that shows the build log of the given
+  paths.</para></listitem>
+
+  
+  <!--
+  <listitem><para>TODO: semantic cleanups of string concatenation
+  etc. (mostly in r6740).</para></listitem>
+  -->
+
+
+  <listitem><para>Nix now uses Berkeley DB 4.5.  The database is
+  upgraded automatically, but you should be careful not to use old
+  versions of Nix that still use Berkeley DB 4.4.</para></listitem>
+
+
+  <!-- foo
+  <listitem><para>TODO: option <option>- -reregister</option> in
+  <command>nix-store - -register-validity</command>.</para></listitem>
+  -->
+
+
+  <listitem><para>The option <option>--max-silent-time</option>
+  (corresponding to the configuration setting
+  <literal>build-max-silent-time</literal>) allows you to set a
+  timeout on builds — if a build produces no output on
+  <literal>stdout</literal> or <literal>stderr</literal> for the given
+  number of seconds, it is terminated.  This is useful for recovering
+  automatically from builds that are stuck in an infinite
+  loop.</para></listitem>
+
+
+  <listitem><para><command>nix-channel</command>: each subscribed
+  channel is its own attribute in the top-level expression generated
+  for the channel.  This allows disambiguation (e.g. <literal>nix-env
+  -i -A nixpkgs_unstable.firefox</literal>).</para></listitem>
+
+
+  <listitem><para>The substitutes table has been removed from the
+  database.  This makes operations such as <command>nix-pull</command>
+  and <command>nix-channel --update</command> much, much
+  faster.</para></listitem>
+
+
+  <listitem><para><command>nix-pull</command> now supports
+  bzip2-compressed manifests.  This speeds up
+  channels.</para></listitem>
+
+
+  <listitem><para><command>nix-prefetch-url</command> now has a
+  limited form of caching.  This is used by
+  <command>nix-channel</command> to prevent unnecessary downloads when
+  the channel hasn’t changed.</para></listitem>
+
+
+  <listitem><para><command>nix-prefetch-url</command> now by default
+  computes the SHA-256 hash of the file instead of the MD5 hash.  In
+  calls to <function>fetchurl</function> you should pass the
+  <literal>sha256</literal> attribute instead of
+  <literal>md5</literal>.  You can pass either a hexadecimal or a
+  base-32 encoding of the hash.</para></listitem>
+
+  
+  <listitem><para>Nix can now perform builds in an automatically
+  generated “chroot”.  This prevents a builder from accessing stuff
+  outside of the Nix store, and thus helps ensure purity.  This is an
+  experimental feature.</para></listitem>
+  
+
+  <listitem><para>The new command <command>nix-store
+  --optimise</command> reduces Nix store disk space usage by finding
+  identical files in the store and hard-linking them to each other.
+  It typically reduces the size of the store by something like
+  25-35%.</para></listitem>
+
+  
+  <listitem><para><filename>~/.nix-defexpr</filename> can now be a
+  directory, in which case the Nix expressions in that directory are
+  combined into an attribute set, with the file names used as the
+  names of the attributes.  The command <command>nix-env
+  --import</command> (which set the
+  <filename>~/.nix-defexpr</filename> symlink) is
+  removed.</para></listitem>
+
+
+  <listitem><para>Derivations can specify the new special attribute
+  <varname>allowedReferences</varname> to enforce that the references
+  in the output of a derivation are a subset of a declared set of
+  paths.  For example, if <varname>allowedReferences</varname> is an
+  empty list, then the output must not have any references.  This is
+  used in NixOS to check that generated files such as initial ramdisks
+  for booting Linux don’t have any dependencies.</para></listitem>
+
+
+  <listitem><para>The new attribute
+  <varname>exportReferencesGraph</varname> allows builders access to
+  the references graph of their inputs.  This is used in NixOS for
+  tasks such as generating ISO-9660 images that contain a Nix store
+  populated with the closure of certain paths.</para></listitem>
+
+
+  <listitem><para>Fixed-output derivations (like
+  <function>fetchurl</function>) can define the attribute
+  <varname>impureEnvVars</varname> to allow external environment
+  variables to be passed to builders.  This is used in Nixpkgs to
+  support proxy configuration, among other things.</para></listitem>
+
+
+  <listitem><para>Several new built-in functions:
+  <function>builtins.attrNames</function>,
+  <function>builtins.filterSource</function>,
+  <function>builtins.isAttrs</function>,
+  <function>builtins.isFunction</function>,
+  <function>builtins.listToAttrs</function>,
+  <function>builtins.stringLength</function>,
+  <function>builtins.sub</function>,
+  <function>builtins.substring</function>,
+  <function>throw</function>,
+  <function>builtins.trace</function>,
+  <function>builtins.readFile</function>.</para></listitem>
+
+
+</itemizedlist>
+
+</section>
+
+
+
+<!--==================================================================-->
+
+<section><title>Release 0.10.1 (October 11, 2006)</title>
+
+<para>This release fixes two somewhat obscure bugs that occur when
+evaluating Nix expressions that are stored inside the Nix store
+(<literal>NIX-67</literal>).  These do not affect most users.</para>
+
+</section>
+
+
+
 <!--==================================================================-->
 
 <section><title>Release 0.10 (October 6, 2006)</title>

doc/manual/style.css

@@ -46,6 +46,11 @@ h3 /* subsections */
     font-size: 125%;
 }
 
+div.simplesect h2
+{
+    font-size: 110%;
+}
+
 div.appendix h3
 {
     font-size: 150%;

doc/manual/troubleshooting.xml

@@ -4,33 +4,9 @@
 <title>Troubleshooting</title>
 
 
-<para>This section provides solutions for some common problems.</para>
-
-
-<section><title>Berkeley DB: <quote>Cannot allocate memory</quote></title>
-
-<para>Symptom: Nix operations (in particular the
-<command>nix-store</command> operations <option>--gc</option>,
-<option>--verify</option>, and <option>--clear-substitutes</option> —
-the latter being called by <command>nix-channel --update</command>)
-failing:
-
-<screen>
-$ nix-store --verify
-error: Db::del: Cannot allocate memory</screen>
-
-</para>
-
-<para>Possible solution: make sure that no Nix processes are running,
-then do:
-
-<screen>
-$ cd /nix/var/nix/db
-$ rm __db.00*</screen>
-
-</para>
-
-</section>
+<para>This section provides solutions for some common problems.  See
+the <link xlink:href="http://bugs.strategoxt.org/browse/NIX">Nix
+bug tracker</link> for a list of currently known issues.</para>
 
 
 <section><title>Collisions in <command>nix-env</command></title>
@@ -100,7 +76,8 @@ Furthermore, the <literal>st_nlink</literal> field of the
 <para>This only happens on very large Nix installations (such as build
 machines).</para>
 
-<para>Quick solution: run the garbage collector.</para>
+<para>Quick solution: run the garbage collector.  You may want to use
+the <option>--max-links</option> option.</para>
 
 <para>Real solution: put the Nix store on a file system that supports
 more than 32,000 subdirectories per directory, such as ReiserFS.

doc/signing.txt

@@ -0,0 +1,24 @@
+Generate a private key:
+
+$ (umask 277 && openssl genrsa -out /nix/etc/nix/signing-key.sec 2048)
+
+The private key should be kept secret (only readable to the Nix daemon
+user).
+
+
+Generate the corresponding public key:
+
+$ openssl rsa -in /nix/etc/nix/signing-key.sec -pubout > /nix/etc/nix/signing-key.pub
+
+The public key should be copied to all machines to which you want to
+export store paths.
+
+
+Signing:
+
+$ nix-hash --type sha256 --flat svn.nar | openssl rsautl -sign -inkey mykey.sec > svn.nar.sign
+
+
+Verifying a signature:
+
+$ test "$(nix-hash --type sha256 --flat svn.nar)" = "$(openssl rsautl -verify -inkey mykey.pub -pubin -in svn.nar.sign)"

externals/Makefile.am

@@ -1,11 +1,13 @@
 # Berkeley DB
 
-DB = db-4.4.20.NC
+DB = db-4.5.20
+
+if OLD_DB_COMPAT
 
 $(DB).tar.gz:
 	@echo "Nix requires Berkeley DB to build."
-	@echo "Please download version 4.4.20 from"
-	@echo "  http://downloads.sleepycat.com/db-4.4.20.NC.tar.gz"
+	@echo "Please download version 4.5.20 from"
+	@echo "  http://download-east.oracle.com/berkeley-db/db-4.5.20.tar.gz"
 	@echo "and place it in the externals/ directory."
 	false
 
@@ -32,22 +34,26 @@ build-db: have-db
 	touch build-db
 endif
 
+else
+
+build-db:
+
+endif
+
 
 # CWI ATerm
 
-ATERM = aterm-2.4.2
+ATERM = aterm-2.4.2-fixes-r2
 
-$(ATERM).tar.gz:
+$(ATERM).tar.bz2:
 	@echo "Nix requires the CWI ATerm library to build."
-	@echo "Please download version 2.4.2 from"
-	@echo "  http://www.cwi.nl/projects/MetaEnv/aterm/aterm-2.4.2.tar.gz"
+	@echo "Please download version 2.4.2-fixes-r2 from"
+	@echo "  http://nixos.org/tarballs/aterm-2.4.2-fixes-r2.tar.bz2"
 	@echo "and place it in the externals/ directory."
 	false
 
-$(ATERM): $(ATERM).tar.gz
-	gunzip < $(srcdir)/$(ATERM).tar.gz | tar xvf -
-	(cd $(ATERM) && $(patch) -p1) < $(srcdir)/aterm-aliasing.patch
-#	(cd $(ATERM) && $(patch) -p1) < $(srcdir)/aterm-64-bit.patch
+$(ATERM): $(ATERM).tar.bz2
+	bunzip2 < $(srcdir)/$(ATERM).tar.bz2 | tar xvf -
 
 have-aterm:
 	$(MAKE) $(ATERM)
@@ -69,12 +75,12 @@ endif
 
 # bzip2
 
-BZIP2 = bzip2-1.0.3
+BZIP2 = bzip2-1.0.5
 
 $(BZIP2).tar.gz:
 	@echo "Nix requires bzip2 to build."
-	@echo "Please download version 1.0.3 from"
-	@echo "  http://www.bzip.org/1.0.3/bzip2-1.0.3.tar.gz"
+	@echo "Please download version 1.0.5 from"
+	@echo "  http://www.bzip.org/1.0.5/bzip2-1.0.5.tar.gz"
 	@echo "and place it in the externals/ directory."
 	false
 
@@ -103,9 +109,9 @@ endif
 
 all: build-db build-aterm build-bzip2
 
-EXTRA_DIST = $(DB).tar.gz $(ATERM).tar.gz $(BZIP2).tar.gz \
-  bdb-cygwin.patch aterm-aliasing.patch aterm-64-bit.patch
+EXTRA_DIST = $(DB).tar.gz $(ATERM).tar.bz2 $(BZIP2).tar.gz \
+  bdb-cygwin.patch
 
 ext-clean:
-	$(RM) -f have-db build-db have-aterm build-aterm
+	$(RM) -f have-db build-db have-aterm build-aterm have-bzip2 build-bzip2
 	$(RM) -rf $(DB) $(ATERM) $(BZIP2)

externals/aterm-64-bit.patch

@@ -1,661 +0,0 @@
-diff -rc aterm-2.4.2-orig/aterm/bafio.c aterm-2.4.2/aterm/bafio.c
-*** aterm-2.4.2-orig/aterm/bafio.c	2004-02-02 12:24:34.000000000 +0100
---- aterm-2.4.2/aterm/bafio.c	2006-09-22 13:39:07.000000000 +0200
-***************
-*** 222,227 ****
---- 222,229 ----
-      }
-    }
-  
-+   if (val) return -1;
-+ 
-    /* Ok */
-    return 0;
-  }
-***************
-*** 544,551 ****
-    * terms have been sorted by symbol.
-  	*/
-  
-! void gather_top_symbols(sym_entry *cur_entry, int cur_arg, 
-! 			int total_top_symbols)
-  {
-    int index;
-    unsigned int hnr;
---- 546,553 ----
-    * terms have been sorted by symbol.
-  	*/
-  
-! static void gather_top_symbols(sym_entry *cur_entry, int cur_arg, 
-! 			       int total_top_symbols)
-  {
-    int index;
-    unsigned int hnr;
-***************
-*** 899,905 ****
-    } else {
-      switch(ATgetType(t)) {
-      case AT_INT:
-!       if(writeBits(ATgetInt((ATermInt)t), HEADER_BITS, writer) < 0) {
-  	return ATfalse;
-        }
-  #if 0
---- 901,908 ----
-    } else {
-      switch(ATgetType(t)) {
-      case AT_INT:
-!       /* If ATerm integers are > 32 bits, then this can fail. */
-!       if(writeBits(ATgetInt((ATermInt)t), INT_SIZE_IN_BAF, writer) < 0) {
-  	return ATfalse;
-        }
-  #if 0
-***************
-*** 1033,1039 ****
-  /*}}}  */
-  /*{{{  ATbool write_baf(ATerm t, byte_writer *writer) */
-  
-! ATbool
-  write_baf(ATerm t, byte_writer *writer)
-  {
-    int nr_unique_terms = 0;
---- 1036,1042 ----
-  /*}}}  */
-  /*{{{  ATbool write_baf(ATerm t, byte_writer *writer) */
-  
-! static ATbool
-  write_baf(ATerm t, byte_writer *writer)
-  {
-    int nr_unique_terms = 0;
-***************
-*** 1233,1239 ****
-  	* Read a single symbol from file.
-  	*/
-  
-! Symbol read_symbol(byte_reader *reader)
-  {
-    unsigned int arity, quoted;
-    int len;
---- 1236,1242 ----
-  	* Read a single symbol from file.
-  	*/
-  
-! static Symbol read_symbol(byte_reader *reader)
-  {
-    unsigned int arity, quoted;
-    int len;
-***************
-*** 1260,1266 ****
-   * Read all symbols from file.
-   */
-  
-! ATbool read_all_symbols(byte_reader *reader)
-  {
-    unsigned int val;
-    int i, j, k, arity;
---- 1263,1269 ----
-   * Read all symbols from file.
-   */
-  
-! static ATbool read_all_symbols(byte_reader *reader)
-  {
-    unsigned int val;
-    int i, j, k, arity;
-***************
-*** 1280,1293 ****
-      /*}}}  */
-      /*{{{  Read term count and allocate space */
-  
-!     if(readInt(&val, reader) < 0)
-        return ATfalse;
-      read_symbols[i].nr_terms = val;
-      read_symbols[i].term_width = bit_width(val);
-!     if(val == 0)
-!       read_symbols[i].terms = NULL;
-!     else
-!       read_symbols[i].terms = (ATerm *)calloc(val, sizeof(ATerm));
-      if(!read_symbols[i].terms)
-        ATerror("read_symbols: could not allocate space for %d terms.\n", val);
-      ATprotectArray(read_symbols[i].terms, val);
---- 1283,1293 ----
-      /*}}}  */
-      /*{{{  Read term count and allocate space */
-  
-!     if(readInt(&val, reader) < 0 || val == 0)
-        return ATfalse;
-      read_symbols[i].nr_terms = val;
-      read_symbols[i].term_width = bit_width(val);
-!     read_symbols[i].terms = (ATerm *)calloc(val, sizeof(ATerm));
-      if(!read_symbols[i].terms)
-        ATerror("read_symbols: could not allocate space for %d terms.\n", val);
-      ATprotectArray(read_symbols[i].terms, val);
-***************
-*** 1351,1357 ****
-  /*}}}  */
-  /*{{{  ATerm read_term(sym_read_entry *sym, byte_reader *reader) */
-  
-! ATerm read_term(sym_read_entry *sym, byte_reader *reader)
-  {
-    unsigned int val;
-    int i, arity = sym->arity;
---- 1351,1357 ----
-  /*}}}  */
-  /*{{{  ATerm read_term(sym_read_entry *sym, byte_reader *reader) */
-  
-! static ATerm read_term(sym_read_entry *sym, byte_reader *reader)
-  {
-    unsigned int val;
-    int i, arity = sym->arity;
-***************
-*** 1365,1370 ****
---- 1365,1371 ----
-      ATprotectArray(args, arity);
-      if(!args)
-        ATerror("could not allocate space for %d arguments.\n", arity);
-+     /* !!! leaks memory on the "return NULL" paths */
-    }
-  
-    /*ATfprintf(stderr, "reading term over symbol %y\n", sym->sym);*/
-***************
-*** 1372,1377 ****
---- 1373,1380 ----
-      /*ATfprintf(stderr, "  reading argument %d (%d)", i, sym->sym_width[i]);*/
-      if(readBits(&val, sym->sym_width[i], reader) < 0)
-        return NULL;
-+     if(val >= sym->nr_topsyms[i])
-+       return NULL;
-      arg_sym = &read_symbols[sym->topsyms[i][val]];
-      /*		ATfprintf(stderr, "argument %d, symbol index = %d, symbol = %y\n", 
-  		i, val, arg_sym->sym);*/
-***************
-*** 1381,1386 ****
---- 1384,1391 ----
-      if(readBits(&val, arg_sym->term_width, reader) < 0)
-        return NULL;
-      /*		ATfprintf(stderr, "arg term index = %d\n", val);*/
-+     if(val >= arg_sym->nr_terms)
-+       return NULL;
-      if(!arg_sym->terms[val]) {
-        arg_sym->terms[val] = read_term(arg_sym, reader);
-        if(!arg_sym->terms[val])
-***************
-*** 1396,1402 ****
-    case AS_INT:
-      /*{{{  Read an integer */
-  
-!     if(readBits(&val, HEADER_BITS, reader) < 0)
-        return NULL;
-  
-      result = (ATerm)ATmakeInt((int)val);
---- 1401,1407 ----
-    case AS_INT:
-      /*{{{  Read an integer */
-  
-!     if(readBits(&val, INT_SIZE_IN_BAF, reader) < 0)
-        return NULL;
-  
-      result = (ATerm)ATmakeInt((int)val);
-***************
-*** 1494,1502 ****
-    for(i=0; i<nr_unique_symbols; i++) {
-      sym_read_entry *entry = &read_symbols[i];
-  
-!     ATunprotectArray(entry->terms);
-!     if(entry->terms)
-        free(entry->terms);
-      if(entry->nr_topsyms)
-        free(entry->nr_topsyms);
-      if(entry->sym_width)
---- 1499,1508 ----
-    for(i=0; i<nr_unique_symbols; i++) {
-      sym_read_entry *entry = &read_symbols[i];
-  
-!     if(entry->terms) {
-!       ATunprotectArray(entry->terms);
-        free(entry->terms);
-+     }
-      if(entry->nr_topsyms)
-        free(entry->nr_topsyms);
-      if(entry->sym_width)
-Only in aterm-2.4.2/aterm: config.h.in
-diff -rc aterm-2.4.2-orig/aterm/encoding.h aterm-2.4.2/aterm/encoding.h
-*** aterm-2.4.2-orig/aterm/encoding.h	2004-06-01 10:29:02.000000000 +0200
---- aterm-2.4.2/aterm/encoding.h	2006-09-22 13:39:07.000000000 +0200
-***************
-*** 10,15 ****
---- 10,17 ----
-  {
-  #endif/* __cplusplus */
-  
-+ #include "config.h"
-+ 
-  /*
-   |--------------------------------|
-   |info|type |arity|quoted|mark|age|
-***************
-*** 31,37 ****
-  #define SHIFT_REMOVE_MARK_AGE 3
-  #define MASK_AGE_MARK   (MASK_AGE|MASK_MARK)
-  
-! #if AT_64BIT
-  #define SHIFT_LENGTH  34
-  #define HEADER_BITS 64
-  typedef unsigned long header_type;
---- 33,39 ----
-  #define SHIFT_REMOVE_MARK_AGE 3
-  #define MASK_AGE_MARK   (MASK_AGE|MASK_MARK)
-  
-! #ifdef AT_64BIT
-  #define SHIFT_LENGTH  34
-  #define HEADER_BITS 64
-  typedef unsigned long header_type;
-***************
-*** 137,142 ****
---- 139,150 ----
-  #define AT_TABLE_SIZE(table_class)  (1<<(table_class))
-  #define AT_TABLE_MASK(table_class)  (AT_TABLE_SIZE(table_class)-1)
-  
-+ 
-+ /* Integers in BAF are always exactly 32 bits.  The size must be fixed so that
-+  * BAF terms can be exchanged between platforms. */
-+ #define INT_SIZE_IN_BAF 32
-+ 
-+ 
-  #ifdef __cplusplus
-  }
-  #endif/* __cplusplus */ 
-diff -rc aterm-2.4.2-orig/aterm/gc.c aterm-2.4.2/aterm/gc.c
-*** aterm-2.4.2-orig/aterm/gc.c	2004-06-01 10:29:02.000000000 +0200
---- aterm-2.4.2/aterm/gc.c	2006-09-22 13:39:07.000000000 +0200
-***************
-*** 154,166 ****
-      }
-  
-  #ifdef AT_64BIT
-!     odd_term = *((ATerm *)((MachineWord)cur)+4);
-      real_term = AT_isInsideValidTerm(odd_term);
-      if (real_term != NULL) {
-        AT_markTerm(odd_term);
-      }
-  
-!     odd_sym = *((AFun *)((MachineWord)cur)+4);
-      if (AT_isValidSymbol(odd_sym)) {
-          /*fprintf(stderr,"mark_memory: AT_markSymbol(%d)\n",odd_sym);*/
-        AT_markSymbol(odd_sym);
---- 154,166 ----
-      }
-  
-  #ifdef AT_64BIT
-!     odd_term = *((ATerm *)(((MachineWord)cur)+4));
-      real_term = AT_isInsideValidTerm(odd_term);
-      if (real_term != NULL) {
-        AT_markTerm(odd_term);
-      }
-  
-!     odd_sym = *((AFun *)(((MachineWord)cur)+4));
-      if (AT_isValidSymbol(odd_sym)) {
-          /*fprintf(stderr,"mark_memory: AT_markSymbol(%d)\n",odd_sym);*/
-        AT_markSymbol(odd_sym);
-***************
-*** 198,210 ****
-      }
-  
-  #ifdef AT_64BIT
-!     odd_term = *((ATerm *)((MachineWord)cur)+4);
-      real_term = AT_isInsideValidTerm(odd_term);
-      if (real_term != NULL) {
-        AT_markTerm_young(odd_term);
-      }
-  
-!     odd_sym = *((AFun *)((MachineWord)cur)+4);
-      if (AT_isValidSymbol(odd_sym)) {
-          /*fprintf(stderr,"mark_memory_young: AT_markSymbol_young(%d)\n",odd_sym);*/
-        AT_markSymbol_young(odd_sym);
---- 198,210 ----
-      }
-  
-  #ifdef AT_64BIT
-!     odd_term = *((ATerm *)(((MachineWord)cur)+4));
-      real_term = AT_isInsideValidTerm(odd_term);
-      if (real_term != NULL) {
-        AT_markTerm_young(odd_term);
-      }
-  
-!     odd_sym = *((AFun *)(((MachineWord)cur)+4));
-      if (AT_isValidSymbol(odd_sym)) {
-          /*fprintf(stderr,"mark_memory_young: AT_markSymbol_young(%d)\n",odd_sym);*/
-        AT_markSymbol_young(odd_sym);
-***************
-*** 225,235 ****
-    ATerm *start, *stop;
-    ProtEntry *prot;
-  
-- #ifdef AT_64BIT
--   ATerm oddTerm;
--   AFun oddSym;
-- #endif
-- 
-  #ifdef WIN32
-  
-    unsigned int r_eax, r_ebx, r_ecx, r_edx, \
---- 225,230 ----
-***************
-*** 287,293 ****
-    /* Traverse possible register variables */
-    sigsetjmp(env,0);
-  
-!   start = (ATerm *)env;
-    stop  = ((ATerm *)(((char *)env) + sizeof(sigjmp_buf)));
-    mark_memory(start, stop);
-  #endif
---- 282,288 ----
-    /* Traverse possible register variables */
-    sigsetjmp(env,0);
-  
-!   start = (ATerm *)env; /* !!! illegal aliasing  */
-    stop  = ((ATerm *)(((char *)env) + sizeof(sigjmp_buf)));
-    mark_memory(start, stop);
-  #endif
-***************
-*** 338,348 ****
-    ATerm *start, *stop;
-    ProtEntry *prot;
-  
-- #ifdef AT_64BIT
--   ATerm oddTerm;
--   AFun oddSym;
-- #endif
-- 
-  #ifdef WIN32
-  
-    unsigned int r_eax, r_ebx, r_ecx, r_edx, \
---- 333,338 ----
-***************
-*** 400,406 ****
-      /* Traverse possible register variables */
-    sigsetjmp(env,0);
-  
-!   start = (ATerm *)env;
-    stop  = ((ATerm *)(((char *)env) + sizeof(sigjmp_buf)));
-    mark_memory_young(start, stop);
-  #endif
---- 390,396 ----
-      /* Traverse possible register variables */
-    sigsetjmp(env,0);
-  
-!   start = (ATerm *)env; /* !!! illegal aliasing  */
-    stop  = ((ATerm *)(((char *)env) + sizeof(sigjmp_buf)));
-    mark_memory_young(start, stop);
-  #endif
-***************
-*** 1047,1053 ****
-        /*fprintf(stderr,"minor_sweep_phase_young: ensure empty freelist[%d]\n",size);*/
-        for(data = at_freelist[size] ; data ; data=data->next) {
-          if(!EQUAL_HEADER(data->header,FREE_HEADER)) {
-!           fprintf(stderr,"data = %x header = %x\n",(unsigned int)data,data->header);
-          }
-          assert(EQUAL_HEADER(data->header,FREE_HEADER)); 
-          assert(ATgetType(data) == AT_FREE);   
---- 1037,1043 ----
-        /*fprintf(stderr,"minor_sweep_phase_young: ensure empty freelist[%d]\n",size);*/
-        for(data = at_freelist[size] ; data ; data=data->next) {
-          if(!EQUAL_HEADER(data->header,FREE_HEADER)) {
-!           fprintf(stderr,"data = %p header = %x\n",data,(unsigned int) data->header);
-          }
-          assert(EQUAL_HEADER(data->header,FREE_HEADER)); 
-          assert(ATgetType(data) == AT_FREE);   
-diff -rc aterm-2.4.2-orig/aterm/Makefile.am aterm-2.4.2/aterm/Makefile.am
-*** aterm-2.4.2-orig/aterm/Makefile.am	2005-08-03 11:45:19.000000000 +0200
---- aterm-2.4.2/aterm/Makefile.am	2006-09-22 13:39:07.000000000 +0200
-***************
-*** 37,43 ****
-    aterm2.h \
-    atypes.h \
-    deprecated.h \
-!   encoding.h
-  
-  PRIVATE_INCL = \
-    _afun.h \
---- 37,44 ----
-    aterm2.h \
-    atypes.h \
-    deprecated.h \
-!   encoding.h \
-!   config.h
-  
-  PRIVATE_INCL = \
-    _afun.h \
-diff -rc aterm-2.4.2-orig/aterm/md5.h aterm-2.4.2/aterm/md5.h
-*** aterm-2.4.2-orig/aterm/md5.h	2003-09-02 15:32:46.000000000 +0200
---- aterm-2.4.2/aterm/md5.h	2006-09-22 13:39:07.000000000 +0200
-***************
-*** 24,29 ****
---- 24,31 ----
-  documentation and/or software.
-   */
-  
-+ #include <stdint.h>
-+ 
-  /* GLOBAL.H - RSAREF types and constants
-   */
-  
-***************
-*** 46,55 ****
-  typedef unsigned char *POINTER;
-  
-  /* UINT2 defines a two byte word */
-! typedef unsigned short int UINT2;
-  
-  /* UINT4 defines a four byte word */
-! typedef unsigned long int UINT4;
-  
-  /* PROTO_LIST is defined depending on how PROTOTYPES is defined above.
-  If using PROTOTYPES, then PROTO_LIST returns the list, otherwise it
---- 48,57 ----
-  typedef unsigned char *POINTER;
-  
-  /* UINT2 defines a two byte word */
-! typedef uint16_t UINT2;
-  
-  /* UINT4 defines a four byte word */
-! typedef uint32_t UINT4;
-  
-  /* PROTO_LIST is defined depending on how PROTOTYPES is defined above.
-  If using PROTOTYPES, then PROTO_LIST returns the list, otherwise it
-diff -rc aterm-2.4.2-orig/aterm/memory.c aterm-2.4.2/aterm/memory.c
-*** aterm-2.4.2-orig/aterm/memory.c	2005-10-11 13:19:25.000000000 +0200
---- aterm-2.4.2/aterm/memory.c	2006-09-22 13:39:16.000000000 +0200
-***************
-*** 96,102 ****
-  #define HASHNUMBER4(t) hash_number(t,4)
-  #define HASHINT(val)   (tmp[0]=(MachineWord)(AT_INT<<SHIFT_TYPE),\
-                          tmp[1]=(MachineWord)0,\
-!                         tmp[2]=(MachineWord)val,\
-                          hash_number(tmp,3)) 
-  
-  #else
---- 96,102 ----
-  #define HASHNUMBER4(t) hash_number(t,4)
-  #define HASHINT(val)   (tmp[0]=(MachineWord)(AT_INT<<SHIFT_TYPE),\
-                          tmp[1]=(MachineWord)0,\
-!                         tmp[2]=(MachineWord)((unsigned int) val),\
-                          hash_number(tmp,3)) 
-  
-  #else
-***************
-*** 127,133 ****
-  		       ((MachineWord*)t)[2]),((MachineWord*)t)[3]))
-  
-  #define HASHINT(val) \
-! FINISH(COMBINE(START( (AT_INT<<SHIFT_TYPE) ), val))
-  
-  
-  #endif /* HASHPEM */
---- 127,133 ----
-  		       ((MachineWord*)t)[2]),((MachineWord*)t)[3]))
-  
-  #define HASHINT(val) \
-! FINISH(COMBINE(START( (AT_INT<<SHIFT_TYPE) ), (unsigned int) val))
-  
-  
-  #endif /* HASHPEM */
-***************
-*** 708,714 ****
-    at_blocks[size] = newblock;
-    top_at_blocks[size] = newblock->data;
-    assert(at_blocks[size] != NULL);
-!   assert(((int)top_at_blocks[size] % MAX(sizeof(double), sizeof(void *))) == 0);
-    
-      /* [pem: Feb 14 02] TODO: fast allocation */
-    assert(at_freelist[size] == NULL);
---- 708,714 ----
-    at_blocks[size] = newblock;
-    top_at_blocks[size] = newblock->data;
-    assert(at_blocks[size] != NULL);
-!   assert(((long)top_at_blocks[size] % MAX(sizeof(double), sizeof(void *))) == 0);
-    
-      /* [pem: Feb 14 02] TODO: fast allocation */
-    assert(at_freelist[size] == NULL);
-***************
-*** 1009,1018 ****
-    do {
-      if(!cur) {
-          /*printf("freeterm = %d\n",t);*/
-!       fprintf(stderr,"### cannot find term %x in hashtable at pos %d header = %x\n", (unsigned int)t, hnr, t->header);
-! 
-!       ATabort("### cannot find term %n at %p in hashtable at pos %d"
-! 	      ", header = %d\n", t, t, hnr, t->header);
-      }
-      if (cur == t) {
-        if(prev)
---- 1009,1016 ----
-    do {
-      if(!cur) {
-          /*printf("freeterm = %d\n",t);*/
-!       ATabort("### cannot find term %p in hashtable at pos %d"
-! 	      ", header = %x\n", t, hnr, t->header);
-      }
-      if (cur == t) {
-        if(prev)
-***************
-*** 1728,1733 ****
---- 1726,1733 ----
-      hashtable[hnr] = cur;
-    }
-  
-+   assert((hnr & table_mask) == (hash_number(cur, TERM_SIZE_INT) & table_mask));
-+ 
-    return (ATermInt)cur;  
-  }
-  
-diff -rc aterm-2.4.2-orig/aterm.m4 aterm-2.4.2/aterm.m4
-*** aterm-2.4.2-orig/aterm.m4	2005-08-03 11:45:19.000000000 +0200
---- aterm-2.4.2/aterm.m4	2006-09-22 13:39:07.000000000 +0200
-***************
-*** 8,15 ****
-      [AS_HELP_STRING([--with-sharing],[create libraries that do term sharing @<:@yes@:>@])],
-      [if test "$withval" = "no"; then
-         AC_MSG_RESULT([no])
-!        AC_DEFINE([NO_SHARING])
-!        AC_DEFINE([WITH_STATS])
-       else
-         if test "$withval" != "yes"; then
-           AC_MSG_RESULT([unknown value specified for --with-sharing.])
---- 8,15 ----
-      [AS_HELP_STRING([--with-sharing],[create libraries that do term sharing @<:@yes@:>@])],
-      [if test "$withval" = "no"; then
-         AC_MSG_RESULT([no])
-!        AC_DEFINE([NO_SHARING], [], [Whether terms are shared.])
-!        AC_DEFINE([WITH_STATS], [], [Whether to keep statistics.])
-       else
-         if test "$withval" != "yes"; then
-           AC_MSG_RESULT([unknown value specified for --with-sharing.])
-***************
-*** 73,78 ****
---- 73,102 ----
-    AC_SUBST([OPTIMIZECFLAGS])
-  ])
-  
-+ # ATERM_64_BIT
-+ # ------------
-+ # Enable 64-bit mode if pointers are 8 bytes large.
-+ AC_DEFUN([ATERM_64_BIT], [
-+   AC_CHECK_SIZEOF(void *)
-+   AC_CHECK_SIZEOF(int)
-+   AC_CHECK_SIZEOF(long)
-+ 
-+   AC_MSG_CHECKING([what kind of platform this is])
-+ 
-+   AC_SUBST([AT_64BIT], [0])
-+   if test "$ac_cv_sizeof_void_p" = "8" -a "$ac_cv_sizeof_int" = "4" -a "$ac_cv_sizeof_long" = "8"; then
-+     AC_MSG_RESULT([LP64])
-+     AC_SUBST([AT_64BIT], [1])
-+   elif test "$ac_cv_sizeof_void_p" = "8" -a "$ac_cv_sizeof_int" = "8" -a "$ac_cv_sizeof_long" = "8"; then
-+     AC_MSG_RESULT([ILP64 - warning, untested])
-+     AC_SUBST([AT_64BIT], [1])
-+   elif test "$ac_cv_sizeof_void_p" = "4" -a "$ac_cv_sizeof_int" = "4" -a "$ac_cv_sizeof_long" = "4"; then
-+     AC_MSG_RESULT([32 bits])
-+   else
-+     AC_MSG_RESULT([something weird - warning, untested])
-+   fi
-+ ])
-+ 
-  # XT_SVN_REVISION
-  # ---------------
-  AC_DEFUN([XT_SVN_REVISION],
-diff -rc aterm-2.4.2-orig/configure.ac aterm-2.4.2/configure.ac
-*** aterm-2.4.2-orig/configure.ac	2005-08-03 11:45:19.000000000 +0200
---- aterm-2.4.2/configure.ac	2006-09-22 13:39:07.000000000 +0200
-***************
-*** 30,35 ****
---- 30,38 ----
-  # Add a configuration option to allow users to control sharing.
-  ATERM_WITH_SHARING
-  
-+ # Enable 64-bit mode if pointers are 8 bytes large.
-+ ATERM_64_BIT
-+ 
-  CURDATE=`date`
-  AC_SUBST([CURDATE])
-  
-***************
-*** 45,49 ****
---- 48,53 ----
-    doc/spec/Makefile
-    aterm.spec
-    aterm.pc
-+   aterm/config.h
-  ])
-  AC_OUTPUT
-diff -rc aterm-2.4.2-orig/utils/dicttoc.c aterm-2.4.2/utils/dicttoc.c
-*** aterm-2.4.2-orig/utils/dicttoc.c	2003-10-07 13:57:40.000000000 +0200
---- aterm-2.4.2/utils/dicttoc.c	2006-09-22 13:39:07.000000000 +0200
-***************
-*** 69,74 ****
---- 69,75 ----
-    fprintf(file, "#ifndef __%s_H\n", code_prefix);
-    fprintf(file, "#define __%s_H\n\n", code_prefix);
-    fprintf(file, "#include <aterm2.h>\n\n");
-+   fprintf(file, "#include <assert.h>\n\n");
-  
-    while (!ATisEmpty(afuns)) {
-      ATerm afun, alias, pair = ATgetFirst(afuns);
-***************
-*** 244,251 ****
-    ATfprintf(file, "{\n");
-    ATfprintf(file, "  ATermList afuns, terms;\n\n");
-  
-!   ATfprintf(file, "  _%s = ATreadFromBinaryString(_%s_baf, _%s_LEN);\n\n", 
-  	    code_prefix, code_prefix, code_prefix);
-    ATfprintf(file, "  ATprotect(&_%s);\n\n", code_prefix);
-  
-    ATfprintf(file, "  afuns = (ATermList)ATelementAt((ATermList)_%s, 0);\n\n", code_prefix);
---- 245,253 ----
-    ATfprintf(file, "{\n");
-    ATfprintf(file, "  ATermList afuns, terms;\n\n");
-  
-!   ATfprintf(file, "  _%s = ATreadFromBinaryString(_%s_baf, _%s_LEN);\n", 
-  	    code_prefix, code_prefix, code_prefix);
-+   ATfprintf(file, "  assert(_%s);\n\n", code_prefix);
-    ATfprintf(file, "  ATprotect(&_%s);\n\n", code_prefix);
-  
-    ATfprintf(file, "  afuns = (ATermList)ATelementAt((ATermList)_%s, 0);\n\n", code_prefix);

externals/aterm-aliasing.patch

@@ -1,224 +0,0 @@
-diff -rc aterm-1142707243.10633/aterm/aterm.c aterm/aterm/aterm.c
-*** aterm-1142707243.10633/aterm/aterm.c	2006-02-08 11:35:28.000000000 +0100
---- aterm/aterm/aterm.c	2006-04-25 17:10:52.000000000 +0200
-***************
-*** 193,198 ****
---- 193,199 ----
-    /* that have char == 2 bytes, and sizeof(header_type) == 2 */
-    assert(sizeof(header_type) == sizeof(ATerm *));
-    assert(sizeof(header_type) >= 4);
-+   assert(sizeof(ATerm) == sizeof(MachineWord));
-  
-    /*}}}  */
-    /*{{{  Initialize buffer */
-diff -rc aterm-1142707243.10633/aterm/memory.c aterm/aterm/memory.c
-*** aterm-1142707243.10633/aterm/memory.c	2006-03-09 15:02:56.000000000 +0100
---- aterm/aterm/memory.c	2006-04-25 18:22:00.000000000 +0200
-***************
-*** 119,130 ****
-                          hash_number(tmp,3)) 
-  */
-  
-  #define HASHNUMBER3(t)\
-! FINISH(COMBINE(START(((MachineWord*)t)[0]), ((MachineWord*)t)[2]))
-  
-  #define HASHNUMBER4(t)\
-! FINISH(COMBINE(COMBINE(START(((MachineWord*)t)[0]), \
-! 		       ((MachineWord*)t)[2]),((MachineWord*)t)[3]))
-  
-  #define HASHINT(val) \
-  FINISH(COMBINE(START( (AT_INT<<SHIFT_TYPE) ), val))
---- 119,171 ----
-                          hash_number(tmp,3)) 
-  */
-  
-+ /* The ATerm library use some heavy aliasing.  For instance, the
-+    various ATermXXX structures are referenced through MachineWord
-+    arrays.  This is not generally allowed by the C standard --- see
-+    C99, section 6.5, clause 7.  In particular, this means that you
-+    cannot assign something through an ATermXXX pointer, e.g.,
-+ 
-+      protoAppl->header = header;
-+ 
-+    and then read it through a MachineWord*, e.g.,
-+ 
-+      hnr = hash_number((ATerm) protoAppl, 2);
-+ 
-+    (hash_number walks over the term by casting it to a MachineWord*).
-+ 
-+    However, the same clause of the C standard also specifies that you
-+    *can* read the memory location through a union type that contains
-+    both the original type (e.g. ATermAppl) and the type used to read
-+    the memory location (e.g. MachineWord).  That's what we do
-+    below: we have a union of all the types that occur in the various
-+    ATerm types.  We then read the "w" element of the union.  The
-+    compiler is not allowed to assume absence of aliasing with the
-+    other types in the union.
-+ 
-+    A better solution would be to hash the term through a character
-+    pointer (since *any* memory location can be legally read as a
-+    character), but I'm too lazy right now.  Performance might also
-+    suffer if we do that. */
-+ 
-+ typedef union 
-+ {
-+     MachineWord w;
-+     header_type header;
-+     ATerm term;
-+     ATermList list;
-+     int i;
-+     double d;
-+     void* p;
-+ } Aliaser;
-+ 
-+ #define GET_WORD(t, n) (((Aliaser*) (((MachineWord*) t) + n))->w)
-+ 
-  #define HASHNUMBER3(t)\
-! FINISH(COMBINE(START(GET_WORD(t, 0)), GET_WORD(t, 2)))
-  
-  #define HASHNUMBER4(t)\
-! FINISH(COMBINE(COMBINE(START(GET_WORD(t, 0)), \
-! 		       GET_WORD(t, 2)), GET_WORD(t, 3)))
-  
-  #define HASHINT(val) \
-  FINISH(COMBINE(START( (AT_INT<<SHIFT_TYPE) ), val))
-***************
-*** 132,144 ****
-  
-  #endif /* HASHPEM */
-  
-! #define PROTO_APPL_ARGS ((ATerm *) (protoTerm + ARG_OFFSET))
-  
-  #define SET_PROTO_APPL_ARG(i, a) \
-!   (PROTO_APPL_ARGS[(i)] = (a))
-  
-  #define GET_PROTO_APPL_ARG(i) \
-!   (PROTO_APPL_ARGS[(i)])
-  
-  #define CHECK_TERM(t) \
-    assert((t) != NULL \
---- 173,185 ----
-  
-  #endif /* HASHPEM */
-  
-! #define PROTO_APPL_ARGS (protoTerm + ARG_OFFSET)
-  
-  #define SET_PROTO_APPL_ARG(i, a) \
-!   (PROTO_APPL_ARGS[(i)] = (MachineWord) (a))
-  
-  #define GET_PROTO_APPL_ARG(i) \
-!   ((ATerm) PROTO_APPL_ARGS[(i)])
-  
-  #define CHECK_TERM(t) \
-    assert((t) != NULL \
-***************
-*** 323,336 ****
-  #else
-  static HashNumber hash_number(ATerm t, int size)
-  {
--   MachineWord *words = (MachineWord *) t;
-    int i;
-    HashNumber hnr;
-  
-!   hnr = START(HIDE_AGE_MARK(words[0]));
-    
-    for (i=2; i<size; i++) {
-!     hnr = COMBINE(hnr, words[i]);
-    }
-  
-    return FINISH(hnr);
---- 364,376 ----
-  #else
-  static HashNumber hash_number(ATerm t, int size)
-  {
-    int i;
-    HashNumber hnr;
-  
-!   hnr = START(HIDE_AGE_MARK(GET_WORD(t, 0)));
-    
-    for (i=2; i<size; i++) {
-!     hnr = COMBINE(hnr, GET_WORD(t, i));
-    }
-  
-    return FINISH(hnr);
-***************
-*** 338,351 ****
-  
-  static HashNumber hash_number_anno(ATerm t, int size, ATerm anno)
-  {
--   MachineWord *words = (MachineWord *) t;
-    int i;
-    HashNumber hnr;
-  
-!   hnr = START(HIDE_AGE_MARK(words[0]));
-    
-    for (i=2; i<size; i++) {
-!     hnr = COMBINE(hnr, words[i]);
-    }
-    hnr = COMBINE(hnr, (MachineWord)anno);
-  
---- 378,390 ----
-  
-  static HashNumber hash_number_anno(ATerm t, int size, ATerm anno)
-  {
-    int i;
-    HashNumber hnr;
-  
-!   hnr = START(HIDE_AGE_MARK(GET_WORD(t, 0)));
-    
-    for (i=2; i<size; i++) {
-!     hnr = COMBINE(hnr, GET_WORD(t, i));
-    }
-    hnr = COMBINE(hnr, (MachineWord)anno);
-  
-***************
-*** 1639,1645 ****
-    protoAppl->header = header;
-    CHECK_HEADER(protoAppl->header);
-  
-!   if (args != PROTO_APPL_ARGS) {
-      for (i=0; i<arity; i++) {
-        CHECK_TERM(args[i]);
-        SET_PROTO_APPL_ARG(i, args[i]);
---- 1678,1684 ----
-    protoAppl->header = header;
-    CHECK_HEADER(protoAppl->header);
-  
-!   if (args != (ATerm *) PROTO_APPL_ARGS) {
-      for (i=0; i<arity; i++) {
-        CHECK_TERM(args[i]);
-        SET_PROTO_APPL_ARG(i, args[i]);
-***************
-*** 1680,1686 ****
-      hashtable[hnr] = cur;
-    }
-  
-!   if (args != PROTO_APPL_ARGS) {
-      for (i=0; i<arity; i++) {
-        protected_buffer[i] = NULL;
-      }
---- 1719,1725 ----
-      hashtable[hnr] = cur;
-    }
-  
-!   if (args != (ATerm *) PROTO_APPL_ARGS) {
-      for (i=0; i<arity; i++) {
-        protected_buffer[i] = NULL;
-      }
-***************
-*** 2144,2150 ****
-    }
-    SET_PROTO_APPL_ARG(n, arg);
-  
-!   result = ATmakeApplArray(sym, PROTO_APPL_ARGS);
-    annos = AT_getAnnotations((ATerm)appl);
-    if (annos != NULL) {
-      result = (ATermAppl)AT_setAnnotations((ATerm)result, annos);
---- 2183,2189 ----
-    }
-    SET_PROTO_APPL_ARG(n, arg);
-  
-!   result = ATmakeApplArray(sym, (ATerm *) PROTO_APPL_ARGS);
-    annos = AT_getAnnotations((ATerm)appl);
-    if (annos != NULL) {
-      result = (ATermAppl)AT_setAnnotations((ATerm)result, annos);

externals/bdb-cygwin.patch

@@ -1,21 +1,22 @@
-diff -rc db-4.4.20.NC-old/os/os_flock.c db-4.4.20.NC/os/os_flock.c
-*** db-4.4.20.NC-old/os/os_flock.c	Mon Jun 20 16:59:01 2005
---- db-4.4.20.NC/os/os_flock.c	Wed Jun  7 17:01:49 2006
+diff -rc db-4.5.20-orig/os/os_flock.c db-4.5.20/os/os_flock.c
+*** db-4.5.20-orig/os/os_flock.c	2006-10-13 12:36:12.000000000 +0200
+--- db-4.5.20/os/os_flock.c	2006-10-13 12:40:11.000000000 +0200
 ***************
-*** 36,41 ****
---- 36,50 ----
+*** 30,35 ****
+--- 30,44 ----
   
-  	DB_ASSERT(F_ISSET(fhp, DB_FH_OPENED) && fhp->fd != -1);
+  	DB_ASSERT(dbenv, F_ISSET(fhp, DB_FH_OPENED) && fhp->fd != -1);
   
 + #ifdef __CYGWIN__
 + 	/*
 + 	 * Windows file locking interferes with read/write operations, so we
 + 	 * map the ranges to an area past the end of the file.
 + 	 */
-+ 	DB_ASSERT(offset < (off_t) 1 << 62);
++ 	DB_ASSERT(dbenv, offset < (off_t) 1 << 62);
 + 	offset += (off_t) 1 << 62;
 + #endif
 + 
-  #ifdef HAVE_FCNTL
   	fl.l_start = offset;
   	fl.l_len = 1;
+  	fl.l_type = acquire ? F_WRLCK : F_UNLCK;
+Only in db-4.5.20/os: os_flock.c~

misc/emacs/nix-mode.el

@@ -76,10 +76,10 @@ The hook `nix-mode-hook' is run when Nix mode is started.
     ("\\<baseNameOf\\>" . font-lock-builtin-face)
     ("\\<toString\\>" . font-lock-builtin-face)
     ("\\<isNull\\>" . font-lock-builtin-face)
-    ("\\<\\([a-zA-Z_][a-zA-Z0-9_']*\\)[ \t]*="
-     (1 font-lock-variable-name-face nil nil))
     ("[a-zA-Z][a-zA-Z0-9\\+-\\.]*:[a-zA-Z0-9%/\\?:@&=\\+\\$,_\\.!~\\*'-]+"
      . font-lock-constant-face)
+    ("\\<\\([a-zA-Z_][a-zA-Z0-9_'\.]*\\)[ \t]*="
+     (1 font-lock-variable-name-face nil nil))
     ("[a-zA-Z0-9._\\+-]*\\(/[a-zA-Z0-9._\\+-]+\\)+"
      . font-lock-constant-face)
     ))

misc/vim/syntax/nix.vim

@@ -0,0 +1,37 @@
+" Vim syntax file
+" Language:	nix
+" Maintainer:	Marc Weber <marco-oweber@gmx.de>
+"               Modify and commit if you feel that way
+" Last Change:	2007 Dec
+
+" Quit when a (custom) syntax file was already loaded
+if exists("b:current_syntax")
+  finish
+endif
+
+syn keyword	nixKeyword	let throw inherit import true false null with
+syn keyword	nixConditional	if else then
+syn keyword     nixBrace        ( ) { } =
+syn keyword     nixBuiltin         __currentSystem __currentTime __isFunction __getEnv __trace __toPath __pathExists 
+  \ __readFile __toXML __toFile __filterSource __attrNames __getAttr __hasAttr __isAttrs __listToAttrs __isList 
+  \ __head __tail __add __sub __lessThan __substring __stringLength
+
+syn match nixAttr "\w\+\ze\s*="
+syn match nixFuncArg "\zs\w\+\ze\s*:"
+syn region nixStringParam start=+\${+ end=+}+
+syn region nixMultiLineComment start=+/\*+ skip=+\\"+ end=+\*/+
+syn match  nixEndOfLineComment "#.*$"
+syn region nixStringIndented start=+''+ skip=+'''\|''${\|"+ end=+''+ contains=nixStringParam
+syn region nixString         start=+"+ skip=+\\"+ end=+"+ contains=nixStringParam
+
+hi def link nixKeyword       Keyword
+hi def link nixConditional   Conditional
+hi def link nixBrace         Special
+hi def link nixString        String
+hi def link nixStringIndented String
+hi def link nixBuiltin       Special
+hi def link nixStringParam   Macro
+hi def link nixMultiLineComment Comment
+hi def link nixEndOfLineComment Comment
+hi def link nixAttr        Identifier
+hi def link nixFuncArg     Identifier

nix.conf.example

@@ -29,25 +29,6 @@
 #gc-keep-derivations = true
 
 
-### Option `gc-reserved-space'
-#
-# This option specifies how much space should be reserved in normal
-# use so that the garbage collector can run succesfully.  Since the
-# garbage collector must perform Berkeley DB transactions, it needs
-# some disk space for itself.  However, when the disk is full, this
-# space is not available, so the collector would not be able to run
-# precisely when it is most needed.
-#
-# For this reason, when Nix is run, it allocates a file
-# /nix/var/nix/db/reserved of the size specified by this option.  When
-# the garbage collector is run, this file is deleted before the
-# Berkeley DB environment is opened.  This should give it enough room
-# to proceed.
-#
-# The default is "1048576" (1 MiB).
-#gc-reserved-space = 1048576
-
-
 ### Option `env-keep-derivations'
 #
 # If `false' (default), derivations are not stored in Nix user
@@ -78,52 +59,112 @@
 #build-max-jobs = 1
 
 
-### Option `build-allow-root'
+### Option `build-max-silent-time'
 #
-# This option controls Nix's behaviour when it is invoked under the
-# `root' user (or setuid-root).  If `true' (default), builds are
-# performed under the `root' user.  If `false', builds are performed
-# under one of the users listed in the `build-users' option (see
-# below).
-#build-allow-root = true
-
-
-### Option `build-users'
+# This option defines the maximum number of seconds that a builder can
+# go without producing any data on standard output or standard error.
+# This is useful (for instance in a automated build system) to catch
+# builds that are stuck in an infinite loop, or to catch remote builds
+# that are hanging due to network problems.  It can be overriden using
+# the `--max-silent-time' command line switch.
 #
-# This option is only applicable if `build-allow-root' is `false' and
-# Nix is invoked under the `root' user (or setuid-root).  It contains
-# a list of user names under which Nix can execute builds.  Builds
-# cannot be performed by root since that would allow users to take
-# over the system by supplying specially crafted builders; and they
-# cannot be performed by the calling user since that would allow
-# him/her to influence the build result.
-#
-# Thus this list should contain a number of `special' user accounts
-# created specifically for Nix, e.g., `nix-builder-1',
-# `nix-builder-2', and so on.  The more users the better, since at
-# most a number of builds equal to the number of build users can be
-# started.
+# The value 0 means that there is no timeout.  This is also the
+# default.
 #
 # Example:
-#   build-users = nix-builder-1 nix-builder-2 nix-builder-3
-#build-users =
+#   build-max-silent-time = 600 # = 10 minutes
+#build-max-silent-time = 0
 
 
-### Option `system'
+### Option `build-users-group'
 #
-# This option specifies the canonical Nix system name of the current
-# installation, such as `i686-linux' or `powerpc-darwin'.  Nix can
-# only build derivations whose `system' attribute equals the value
-# specified here.  In general, it never makes sense to modify this
-# value from its default, since you can use it to `lie' about the
-# platform you are building on (e.g., perform a Mac OS build on a
-# Linux machine; the result would obviously be wrong).  It only makes
-# sense if the Nix binaries can run on multiple platforms, e.g.,
-# `universal binaries' that run on `powerpc-darwin' and `i686-darwin'.
+# This options specifies the Unix group containing the Nix build user
+# accounts.  In multi-user Nix installations, builds should not
+# be performed by the Nix account since that would allow users to
+# arbitrarily modify the Nix store and database by supplying specially
+# crafted builders; and they cannot be performed by the calling user
+# since that would allow him/her to influence the build result.
 #
-# It defaults to the canonical Nix system name detected by `configure'
-# at build time.
+# Therefore, if this option is non-empty and specifies a valid group,
+# builds will be performed under the user accounts that are a member
+# of the group specified here (as listed in /etc/group).  Those user
+# accounts should not be used for any other purpose!
+#
+# Nix will never run two builds under the same user account at the
+# same time.  This is to prevent an obvious security hole: a malicious
+# user writing a Nix expression that modifies the build result of a
+# legitimate Nix expression being built by another user.  Therefore it
+# is good to have as many Nix build user accounts as you can spare.
+# (Remember: uids are cheap.)
+#
+# The build users should have permission to create files in the Nix
+# store, but not delete them.  Therefore, /nix/store should be owned
+# by the Nix account, its group should be the group specified here,
+# and its mode should be 1775.
+#
+# If the build users group is empty, builds will be performed under
+# the uid of the Nix process (that is, the uid of the caller if
+# $NIX_REMOTE is empty, the uid under which the Nix daemon runs if
+# $NIX_REMOTE is `daemon', or the uid that owns the setuid nix-worker
+# program if $NIX_REMOTE is `slave').  Obviously, this should not be
+# used in multi-user settings with untrusted users.
+#
+# The default is empty.
 #
 # Example:
-#   system = i686-darwin
-#system =
+#   build-users-group = nix-builders
+#build-users-group =
+
+
+### Option `build-use-chroot'
+#
+# If set to `true', builds will be performed in a chroot environment,
+# i.e., the build will be isolated from the normal file system
+# hierarchy and will only see the Nix store, the temporary build
+# directory, and the directories configured with the
+# `build-chroot-dirs' option (such as /proc and /dev).  This is useful
+# to prevent undeclared dependencies on files in directories such as
+# /usr/bin.
+#
+# The use of a chroot requires that Nix is run as root (but you can
+# still use the "build users" feature to perform builds under
+# different users than root).  Currently, chroot builds only work on
+# Linux because Nix uses "bind mounts" to make the Nix store and other
+# directories available inside the chroot.
+#
+# The default is `false'.
+#
+# Example:
+#   build-use-chroot = true
+#build-use-chroot = false
+
+
+### Option `build-chroot-dirs'
+#
+# When builds are performed in a chroot environment, Nix will mount
+# (using `mount --bind' on Linux) some directories from the normal
+# file system hierarchy inside the chroot.  These are the Nix store,
+# the temporary build directory (usually /tmp/nix-<pid>-<number>) and
+# the directories listed here.  The default is "/dev /dev/pts /proc".
+# Files in /dev (such as /dev/null) are needed by many builds, and
+# some files in /proc may also be needed occasionally.
+#
+# Example:
+#   build-use-chroot = /dev /proc /bin
+#build-chroot-dirs = /dev /dev/pts /proc
+
+
+### Option `build-cache-failure'
+#
+# If this option is enabled, Nix will do negative caching; that is, it
+# will remember failed builds, and won't attempt to try to build them
+# again if you ask for it.  Negative caching is disabled by default
+# because Nix cannot distinguish between permanent build errors (e.g.,
+# a syntax error in a source file) and transient build errors (e.g., a
+# full disk), as they both cause the builder to return a non-zero exit
+# code.  You can clear the cache by doing `rm -f
+# /nix/var/nix/db/failed/*'.
+#
+# Example:
+#   build-cache-failure = true
+#build-cache-failure = false

nix.spec.in

@@ -13,11 +13,10 @@ Version: @version@
 Release: 1
 License: GPL
 Group: Software Deployment
-URL: http://www.cs.uu.nl/groups/ST/Trace/Nix
+URL: http://nixos.org/
 Source0: %{name}-@version@.tar.bz2
 BuildRoot: %{_tmppath}/%{name}-%{version}-buildroot
-%define _prefix /nix
-Prefix: %{_prefix}
+Prefix: /usr
 Requires: /usr/bin/perl
 Requires: curl
 
@@ -26,7 +25,12 @@ Provides: perl(readmanifest)
                                                                
 %description
 
-Nix is a system for software deployment.
+Nix is a purely functional package manager. It allows multiple
+versions of a package to be installed side-by-side, ensures that
+dependency specifications are complete, supports atomic upgrades and
+rollbacks, allows non-root users to install software, and has many
+other features. It is the basis of the NixOS Linux distribution, but
+it can be used equally well under other Unix systems.
 
 %prep
 %setup -q
@@ -42,14 +46,14 @@ if test -n "%{enable_setuid}"; then
         extraFlags="$extraFlags --with-nix-group=%{nix_group}"
     fi
 fi
-./configure --prefix=%{_prefix} $extraFlags
+./configure --prefix=%{_prefix} --sysconfdir=/etc $extraFlags
 make
 make check
 
 %install
 rm -rf $RPM_BUILD_ROOT
 make DESTDIR=$RPM_BUILD_ROOT install
-rm $RPM_BUILD_ROOT/%{_prefix}/etc/nix/nix.conf
+rm $RPM_BUILD_ROOT/etc/nix/nix.conf
 strip $RPM_BUILD_ROOT/%{_prefix}/bin/* || true
 
 %clean
@@ -71,11 +75,9 @@ fi
 %{_prefix}/lib
 %{_prefix}/libexec
 %{_prefix}/include
-%{_prefix}/var
 %{_prefix}/share
-%{_prefix}/man
-%{_prefix}/store
+/etc/profile.d/nix.sh
+/nix/var
+/nix/store
 %config
-%{_prefix}/etc
-#%doc
-#%{_prefix}/share/nix/manual
+/etc/nix

release.nix

@@ -0,0 +1,196 @@
+{ nixpkgs ? ../nixpkgs }:
+
+let
+
+  jobs = rec {
+
+
+    tarball =
+      { nix ? {outPath = ./.; rev = 1234;}
+      , officialRelease ? false
+      }:
+
+      with import nixpkgs {};
+
+      releaseTools.sourceTarball {
+        name = "nix-tarball";
+        version = builtins.readFile ./version;
+        src = nix;
+        inherit officialRelease;
+
+        buildInputs = [curl bison flex2533 perl libxml2 libxslt w3m bzip2 jing_tools tetex dblatex];
+
+        configureFlags = ''
+          --with-docbook-rng=${docbook5}/xml/rng/docbook
+          --with-docbook-xsl=${docbook5_xsl}/xml/xsl/docbook
+          --with-xml-flags=--nonet
+        '';
+
+        # Include the BDB, ATerm and Bzip2 tarballs in the distribution.
+        preConfigure = ''
+          stripHash ${db45.src}
+          # Remove unnecessary stuff from the Berkeley DB tarball.
+          ( mkdir bdb-temp
+            cd bdb-temp
+            tar xfz ${db45.src}
+            cd *
+            rm -rf docs test tcl perl libdb_java java rpc_server build_vxworks \
+              examples_java examples_c examples_cxx dist/tags
+            mkdir test
+            touch test/include.tcl
+            cd ..
+            tar cvfz ../externals/$strippedName *
+          )
+
+          stripHash ${aterm242fixes.src}
+          cp -pv ${aterm242fixes.src} externals/$strippedName
+
+          stripHash ${bzip2.src}
+          cp -pv ${bzip2.src} externals/$strippedName
+        '';
+
+        preDist = ''
+          make -C doc/manual install prefix=$out
+          
+          make -C doc/manual manual.pdf prefix=$out
+          cp doc/manual/manual.pdf $out/manual.pdf
+          
+          echo "doc manual $out/share/doc/nix/manual" >> $out/nix-support/hydra-build-products
+          echo "doc-pdf manual $out/manual.pdf" >> $out/nix-support/hydra-build-products
+          echo "doc release-notes $out/share/doc/nix/release-notes" >> $out/nix-support/hydra-build-products
+        '';
+      };
+
+
+    build =
+      { tarball ? jobs.tarball {}
+      , system ? "i686-linux"
+      }:
+
+      with import nixpkgs {inherit system;};
+
+      releaseTools.nixBuild {
+        name = "nix";
+        src = tarball;
+
+        buildInputs = [curl perl bzip2 openssl];
+
+        configureFlags = ''
+          --disable-init-state
+          --with-bdb=${db45} --with-aterm=${aterm242fixes} --with-bzip2=${bzip2}
+        '';
+      };
+
+      
+    static =
+      { tarball ? jobs.tarball {}
+      , system ? "i686-linux"
+      }:
+
+      with import nixpkgs {inherit system;};
+
+      releaseTools.binaryTarball {
+        name = "nix-static-tarball";
+        src = tarball;
+
+        buildInputs = [curl perl bzip2];
+
+        configureFlags = ''
+          --disable-init-state
+          --disable-old-db-compat --with-aterm=${aterm242fixes} --with-bzip2=${bzip2}
+          --enable-static-nix
+        '';
+      };
+
+      
+    coverage =
+      { tarball ? jobs.tarball {}
+      }:
+
+      with import nixpkgs {};
+
+      releaseTools.coverageAnalysis {
+        name = "nix-build";
+        src = tarball;
+
+        buildInputs = [
+          curl perl bzip2 openssl
+          # These are for "make check" only:
+          graphviz libxml2 libxslt
+        ];
+
+        configureFlags = ''
+          --disable-init-state --disable-shared
+          --with-bdb=${db45} --with-aterm=${aterm242fixes} --with-bzip2=${bzip2}
+        '';
+
+        lcovFilter = ["*/boost/*" "*-tab.*"];
+
+        # We call `dot', and even though we just use it to
+        # syntax-check generated dot files, it still requires some
+        # fonts.  So provide those.
+        FONTCONFIG_FILE = texFunctions.fontsConf;
+      };
+
+      
+    rpm_fedora5i386 = makeRPM_i686 (diskImages: diskImages.fedora5i386) 20;
+    rpm_fedora9i386 = makeRPM_i686 (diskImages: diskImages.fedora9i386) 50;
+    rpm_fedora9x86_64 = makeRPM_x86_64 (diskImages: diskImages.fedora9x86_64) 50;
+    rpm_fedora10i386 = makeRPM_i686 (diskImages: diskImages.fedora10i386) 40;
+    rpm_fedora10x86_64 = makeRPM_x86_64 (diskImages: diskImages.fedora10x86_64) 40;
+    rpm_opensuse103i386 = makeRPM_i686 (diskImages: diskImages.opensuse103i386) 40;
+
+    
+    deb_debian40i386 = makeDeb_i686 (diskImages: diskImages.debian40i386) 40;
+    deb_debian40x86_64 = makeDeb_x86_64 (diskImages: diskImages.debian40x86_64) 40;
+    deb_debian50i386 = makeDeb_i686 (diskImages: diskImages.debian50i386) 30;
+    deb_debian50x86_64 = makeDeb_x86_64 (diskImages: diskImages.debian50x86_64) 30;
+    deb_ubuntu804i386 = makeDeb_i686 (diskImages: diskImages.ubuntu804i386) 50;
+    deb_ubuntu804x86_64 = makeDeb_x86_64 (diskImages: diskImages.ubuntu804x86_64) 50;
+    deb_ubuntu810i386 = makeDeb_i686 (diskImages: diskImages.ubuntu810i386) 40;
+    deb_ubuntu810x86_64 = makeDeb_x86_64 (diskImages: diskImages.ubuntu810x86_64) 40;
+
+
+  };
+
+
+  makeRPM_i686 = makeRPM "i686-linux";
+  makeRPM_x86_64 = makeRPM "x86_64-linux";
+
+  makeRPM = 
+    system: diskImageFun: prio:
+    { tarball ? jobs.tarball {}
+    }:
+
+    with import nixpkgs {inherit system;};
+
+    releaseTools.rpmBuild rec {
+      name = "nix-rpm-${diskImage.name}";
+      src = tarball;
+      diskImage = diskImageFun vmTools.diskImages;
+      memSize = 1024;
+      meta = { schedulingPriority = toString prio; };
+    };
+
+
+  makeDeb_i686 = makeDeb "i686-linux";
+  makeDeb_x86_64 = makeDeb "x86_64-linux";
+  
+  makeDeb =
+    system: diskImageFun: prio:
+    { tarball ? jobs.tarball {}
+    }:
+
+    with import nixpkgs {inherit system;};
+
+    releaseTools.debBuild {
+      name = "nix-deb";
+      src = tarball;
+      diskImage = diskImageFun vmTools.diskImages;
+      memSize = 1024;
+      meta = { schedulingPriority = toString prio; };
+      configureFlags = "--sysconfdir=/etc";
+    };
+
+
+in jobs

scripts/Makefile.am

@@ -1,20 +1,26 @@
 bin_SCRIPTS = nix-collect-garbage \
   nix-pull nix-push nix-prefetch-url \
   nix-install-package nix-channel nix-build \
-  nix-pack-closure nix-unpack-closure
+  nix-copy-closure 
 
-noinst_SCRIPTS = nix-profile.sh generate-patches.pl find-runtime-roots.pl
+noinst_SCRIPTS = nix-profile.sh generate-patches.pl \
+  find-runtime-roots.pl build-remote.pl nix-reduce-build \
+  copy-from-other-stores.pl nix-http-export.cgi
 
 nix-pull nix-push: readmanifest.pm readconfig.pm download-using-manifests.pl
 
-install-exec-local: readmanifest.pm download-using-manifests.pl find-runtime-roots.pl
+install-exec-local: readmanifest.pm download-using-manifests.pl copy-from-other-stores.pl find-runtime-roots.pl
 	$(INSTALL) -d $(DESTDIR)$(sysconfdir)/profile.d
 	$(INSTALL_PROGRAM) nix-profile.sh $(DESTDIR)$(sysconfdir)/profile.d/nix.sh
 	$(INSTALL) -d $(DESTDIR)$(libexecdir)/nix
 	$(INSTALL_DATA) readmanifest.pm $(DESTDIR)$(libexecdir)/nix 
 	$(INSTALL_DATA) readconfig.pm $(DESTDIR)$(libexecdir)/nix 
-	$(INSTALL_PROGRAM) download-using-manifests.pl $(DESTDIR)$(libexecdir)/nix 
 	$(INSTALL_PROGRAM) find-runtime-roots.pl $(DESTDIR)$(libexecdir)/nix 
+	$(INSTALL_PROGRAM) generate-patches.pl $(DESTDIR)$(libexecdir)/nix 
+	$(INSTALL_PROGRAM) build-remote.pl $(DESTDIR)$(libexecdir)/nix 
+	$(INSTALL) -d $(DESTDIR)$(libexecdir)/nix/substituters
+	$(INSTALL_PROGRAM) download-using-manifests.pl $(DESTDIR)$(libexecdir)/nix/substituters
+	$(INSTALL_PROGRAM) copy-from-other-stores.pl $(DESTDIR)$(libexecdir)/nix/substituters
 	$(INSTALL) -d $(DESTDIR)$(sysconfdir)/nix
 
 include ../substitute.mk
@@ -27,6 +33,10 @@ EXTRA_DIST = nix-collect-garbage.in \
   readconfig.pm.in \
   nix-build.in \
   download-using-manifests.pl.in \
+  copy-from-other-stores.pl.in \
   generate-patches.pl.in \
-  nix-pack-closure.in nix-unpack-closure.in \
-  find-runtime-roots.pl.in
+  nix-copy-closure.in \
+  find-runtime-roots.pl.in \
+  build-remote.pl.in \
+  nix-reduce-build.in \
+  nix-http-export.cgi.in 

scripts/build-remote.pl.in

@@ -0,0 +1,212 @@
+#! @perl@ -w
+
+use strict;
+use Fcntl ':flock';
+use English '-no_match_vars';
+use IO::Handle;
+
+# General operation:
+#
+# Try to find a free machine of type $neededSystem.  We do this as
+# follows:
+# - We acquire an exclusive lock on $currentLoad/main-lock.
+# - For each machine $machine of type $neededSystem and for each $slot
+#   less than the maximum load for that machine, we try to get an
+#   exclusive lock on $currentLoad/$machine-$slot (without blocking).
+#   If we get such a lock, we send "accept" to the caller.  Otherwise,
+#   we send "postpone" and exit. 
+# - We release the exclusive lock on $currentLoad/main-lock.
+# - We perform the build on $neededSystem.
+# - We release the exclusive lock on $currentLoad/$machine-$slot.
+#
+# The nice thing about this scheme is that if we die prematurely, the
+# locks are released automatically.
+
+my $loadIncreased = 0;
+
+my ($amWilling, $localSystem, $neededSystem, $drvPath, $maxSilentTime) = @ARGV;
+$maxSilentTime = 0 unless defined $maxSilentTime;
+
+sub sendReply {
+    my $reply = shift;
+    print STDERR "# $reply\n";
+}
+
+sub decline {
+    sendReply "decline";
+    exit 0;
+}
+
+my $currentLoad = $ENV{"NIX_CURRENT_LOAD"};
+decline unless defined $currentLoad;
+mkdir $currentLoad, 0777 or die unless -d $currentLoad;
+
+my $conf = $ENV{"NIX_REMOTE_SYSTEMS"};
+decline if !defined $conf || ! -e $conf;
+
+my $canBuildLocally = $amWilling && ($localSystem eq $neededSystem);
+
+
+# Otherwise find a willing remote machine.
+my @machines;
+my %curJobs;
+
+
+# Read the list of machines.
+open CONF, "< $conf" or die;
+
+while (<CONF>) {
+    chomp;
+    s/\#.*$//g;
+    next if /^\s*$/;
+    /^\s*(\S+)\s+(\S+)\s+(\S+)\s+(\d+)\s*$/ or die;
+    push @machines,
+        { hostName => $1
+        , systemType => $2
+        , sshKeys => $3
+        , maxJobs => $4
+        };
+}
+
+close CONF;
+
+
+# Acquire the exclusive lock on $currentLoad/main-lock.
+my $mainLock = "$currentLoad/main-lock";
+open MAINLOCK, ">>$mainLock" or die;
+flock(MAINLOCK, LOCK_EX) or die;
+
+
+# Find a suitable system.
+my $rightType = 0;
+my $machine;
+my $slotLock;
+LOOP: foreach my $cur (@machines) {
+    if ($neededSystem eq $cur->{systemType}
+        || ($neededSystem eq "i686-linux" && $cur->{systemType} eq "x86_64-linux"))
+    {
+        $rightType = 1;
+
+        # We have a machine of the right type.  Try to get a lock on
+        # one of the machine's lock files.
+        my $slot = 0;
+        while ($slot < $cur->{maxJobs}) {
+            my $slotLockFn = "$currentLoad/" . $cur->{systemType} . "-" . $cur->{hostName} . "-$slot";
+            $slotLock = new IO::Handle;
+            open $slotLock, ">>$slotLockFn" or die;
+            if (flock($slotLock, LOCK_EX | LOCK_NB)) {
+                utime undef, undef, $slotLock;
+                $machine = $cur;
+                last LOOP;
+            }
+            close $slotLock;
+            $slot++;
+        }
+    }
+}
+
+close MAINLOCK;
+
+
+# Didn't find one?  Then decline or postpone.
+if (!defined $machine) {
+    # Postpone if we have a machine of the right type, except if the
+    # local system can and wants to do the build.
+    if ($rightType && !$canBuildLocally) {
+        sendReply "postpone";
+        exit 0;
+    } else {
+        decline;
+    }
+}
+
+# Yes we did, accept.
+sendReply "accept";
+my $x = <STDIN>;
+chomp $x;
+
+if ($x ne "okay") {
+    exit 0;
+}
+
+
+# Do the actual job.
+my $hostName = $machine->{hostName};
+print STDERR "building `$drvPath' on `$hostName'\n";
+
+# Make sure that we don't get any SSH passphrase or host key popups -
+# if there is any problem it should fail, not do something
+# interactive.
+$ENV{"DISPLAY"} = "";
+$ENV{"SSH_PASSWORD_FILE="} = "";
+$ENV{"SSH_ASKPASS="} = "";
+
+my $sshOpts = "-i " . $machine->{sshKeys} . " -x";
+
+# Hack to support Cygwin: if we login without a password, we don't
+# have exactly the same rights as when we do.  This causes the
+# Microsoft C compiler to fail with certain flags:
+#
+#   http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=99676
+#
+# So as a workaround, we pass a verbatim password.  ssh tries to makes
+# this very hard; the trick is to make it call SSH_ASKPASS to get the
+# password.  (It only calls this command when there is no controlling
+# terminal, but Nix ensures that is is the case.  When doing this
+# manually, use setsid(1).)
+if ($machine->{sshKeys} =~ /^password:/) {
+    my $passwordFile = $machine->{sshKeys};
+    $passwordFile =~ s/^password://;
+    $sshOpts = "ssh -x";
+    $ENV{"SSH_PASSWORD_FILE"} = $passwordFile;
+    $ENV{"SSH_ASKPASS"} = "/tmp/writepass";
+
+    open WRITEPASS, ">/tmp/writepass" or die;
+    print WRITEPASS "#! /bin/sh\ncat \"\$SSH_PASSWORD_FILE\"";
+    close WRITEPASS;
+    chmod 0755, "/tmp/writepass" or die;
+}
+
+my $inputs = `cat inputs`; die if ($? != 0);
+$inputs =~ s/\n/ /g;
+
+my $outputs = `cat outputs`; die if ($? != 0);
+$outputs =~ s/\n/ /g;
+
+print "copying inputs...\n";
+
+my $maybeSign = "";
+$maybeSign = "--sign" if -e "/nix/etc/nix/signing-key.sec";
+
+system("NIX_SSHOPTS=\"$sshOpts\" @bindir@/nix-copy-closure --gzip $hostName $maybeSign $drvPath $inputs") == 0
+    or die "cannot copy inputs to $hostName: $?";
+
+print "building...\n";
+
+my $buildFlags = "--max-silent-time $maxSilentTime";
+
+# `-tt' forces allocation of a pseudo-terminal.  This is required to
+# make the remote nix-store process receive a signal when the
+# connection dies.  Without it, the remote process might continue to
+# run indefinitely (that is, until it next tries to write to
+# stdout/stderr).
+if (system("ssh -tt $sshOpts $hostName 'nix-store --realise -K $buildFlags $drvPath > /dev/null'") != 0) {
+    # If we couldn't run ssh or there was an ssh problem (indicated by
+    # exit code 255), then we return exit code 1; otherwise we assume
+    # that the builder failed, which we indicated to Nix using exit
+    # code 100.  It's important to distinguish between the two because
+    # the first is a transient failure and the latter is permanent.
+    my $res = $? == -1 || ($? >> 8) == 255 ? 1 : 100;
+    print STDERR "build of `$drvPath' on `$hostName' failed with exit code $?\n";
+    exit $res;
+}
+
+print "build of `$drvPath' on `$hostName' succeeded\n";
+
+foreach my $output (split '\n', $outputs) {
+    my $maybeSignRemote = "";
+    $maybeSignRemote = "--sign" if $UID != 0;
+    
+    system("ssh $sshOpts $hostName 'nix-store --export $maybeSignRemote $output | gzip' | gunzip | @bindir@/nix-store --import > /dev/null") == 0
+	or die "cannot copy $output from $hostName: $?";
+}

scripts/copy-from-other-stores.pl.in

@@ -0,0 +1,98 @@
+#! @perl@ -w
+
+use strict;
+use File::Basename;
+use IO::Handle;
+
+my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
+
+
+STDOUT->autoflush(1);
+
+my @remoteStoresAll = split ':', ($ENV{"NIX_OTHER_STORES"} or "");
+
+my @remoteStores;
+foreach my $dir (@remoteStoresAll) {
+    push @remoteStores, glob($dir);
+}
+
+
+sub findStorePath {
+    my $storePath = shift;
+    
+    my $storePathName = basename $storePath;
+    
+    foreach my $store (@remoteStores) {
+        # Determine whether $storePath exists by looking for the
+        # existence of the info file, and if so, get store path info
+        # from that file.  This rather breaks abstraction: we should
+        # be using `nix-store' for that.  But right now there is no
+        # good way to tell nix-store to access a store mounted under a
+        # different location (there's $NIX_STORE, but that only works
+        # if the remote store is mounted under its "real" location).
+        my $infoFile = "$store/var/nix/db/info/$storePathName";
+        my $storePath2 = "$store/store/$storePathName";
+        if (-f $infoFile && -e $storePath2) {
+            return ($infoFile, $storePath2);
+        }
+    }
+}
+
+
+if ($ARGV[0] eq "--query") {
+
+    while (<STDIN>) {
+        my $cmd = $_; chomp $cmd;
+
+        if ($cmd eq "have") {
+            my $storePath = <STDIN>; chomp $storePath;
+            (my $infoFile) = findStorePath $storePath;
+            print STDOUT ($infoFile ? "1\n" : "0\n");
+        }
+
+        elsif ($cmd eq "info") {
+            my $storePath = <STDIN>; chomp $storePath;
+            (my $infoFile) = findStorePath $storePath;
+            if (!$infoFile) {
+                print "0\n";
+                next; # not an error
+            }
+            print "1\n";
+
+            my $deriver = "";
+            my @references = ();
+
+            open INFO, "<$infoFile" or die "cannot read info file $infoFile\n";
+            while (<INFO>) {
+                chomp;
+                /^([\w-]+): (.*)$/ or die "bad info file";
+                my $key = $1;
+                my $value = $2;
+                if ($key eq "Deriver") { $deriver = $value; }
+                elsif ($key eq "References") { @references = split ' ', $value; }
+            }
+            close INFO;
+
+            print "$deriver\n";
+            print scalar @references, "\n";
+            print "$_\n" foreach @references;
+            print "0\n"; # !!! showing size not supported (yet)
+        }
+
+        else { die "unknown command `$cmd'"; }
+    }
+}
+
+
+elsif ($ARGV[0] eq "--substitute") {
+    die unless scalar @ARGV == 2;
+    my $storePath = $ARGV[1];
+    (my $infoFile, my $sourcePath) = findStorePath $storePath;
+    die unless $infoFile;
+    print "\n*** Copying `$storePath' from `$sourcePath'\n\n";
+    system("$binDir/nix-store --dump $sourcePath | $binDir/nix-store --restore $storePath") == 0
+        or die "cannot copy `$sourcePath' to `$storePath'";
+}
+
+
+else { die; }

scripts/download-using-manifests.pl.in

@@ -5,12 +5,81 @@ use readmanifest;
 use POSIX qw(strftime);
 use File::Temp qw(tempdir);
 
-my $manifestDir = "@localstatedir@/nix/manifests";
+my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
+
+STDOUT->autoflush(1);
+
+my $manifestDir = ($ENV{"NIX_MANIFESTS_DIR"} or "@localstatedir@/nix/manifests");
 my $logFile = "@localstatedir@/log/nix/downloads";
 
-open LOGFILE, ">>$logFile" or die "cannot open log file $logFile";
 
-delete $ENV{"NIX_ROOT"};
+# Load all manifests.
+my %narFiles;
+my %localPaths;
+my %patches;
+
+for my $manifest (glob "$manifestDir/*.nixmanifest") {
+    my $version = readManifest($manifest, \%narFiles, \%localPaths, \%patches);
+    if ($version < 3) {
+        print STDERR "you have an old-style manifest `$manifest'; please delete it\n";
+        exit 1;
+    }
+    if ($version >= 10) {
+        print STDERR "manifest `$manifest' is too new; please delete it or upgrade Nix\n";
+        exit 1;
+    }
+}
+
+
+# Parse the arguments.
+
+if ($ARGV[0] eq "--query") {
+
+    while (<STDIN>) {
+        my $cmd = $_; chomp $cmd;
+
+        if ($cmd eq "have") {
+            my $storePath = <STDIN>; chomp $storePath;
+            print STDOUT ((defined $narFiles{$storePath} or defined $localPaths{$storePath})
+                ? "1\n" : "0\n");
+        }
+
+        elsif ($cmd eq "info") {
+            my $storePath = <STDIN>; chomp $storePath;
+            my $info;
+            if (defined $narFiles{$storePath}) {
+                $info = @{$narFiles{$storePath}}[0];
+            }
+            elsif (defined $localPaths{$storePath}) {
+                $info = @{$localPaths{$storePath}}[0];
+            }
+            else {
+                print "0\n";
+                next; # not an error
+            }
+            print "1\n";
+            print "$info->{deriver}\n";
+            my @references = split " ", $info->{references};
+            print scalar @references, "\n";
+            print "$_\n" foreach @references;
+            my $size = $info->{size} || 0;
+            print "$size\n";
+        }
+        
+        else { die "unknown command `$cmd'"; }
+    }
+
+    exit 0;
+}
+
+elsif ($ARGV[0] ne "--substitute") {
+    die "syntax: $0 [--query-paths | --query-info PATHS... | --substitute PATH]\n";
+}
+
+
+die unless scalar @ARGV == 2;
+my $targetPath = $ARGV[1];
+
 
 # Create a temporary directory.
 my $tmpDir = tempdir("nix-download.XXXXXX", CLEANUP => 1, TMPDIR => 1)
@@ -21,12 +90,8 @@ chdir $tmpDir or die "cannot change to `$tmpDir': $!";
 my $tmpNar = "$tmpDir/nar";
 my $tmpNar2 = "$tmpDir/nar2";
 
-END { unlink $tmpNar; unlink $tmpNar2; rmdir $tmpDir; }
 
-
-# Check the arguments.
-die unless scalar @ARGV == 1;
-my $targetPath = $ARGV[0];
+open LOGFILE, ">>$logFile" or die "cannot open log file $logFile";
 
 my $date = strftime ("%F %H:%M:%S UTC", gmtime (time));
 print LOGFILE "$$ get $targetPath $date\n";
@@ -34,16 +99,15 @@ print LOGFILE "$$ get $targetPath $date\n";
 print "\n*** Trying to download/patch `$targetPath'\n";
 
 
-# Load all manifests.
-my %narFiles;
-my %patches;
-my %successors;
-
-for my $manifest (glob "$manifestDir/*.nixmanifest") {
-#    print STDERR "reading $manifest\n";
-    if (readManifest($manifest, \%narFiles, \%patches, \%successors) < 3) {
-        print STDERR "you have an old-style manifest `$manifest'; please delete it\n";
-        exit 1;
+# If we can copy from a local path, do that.
+my $localPathList = $localPaths{$targetPath};
+foreach my $localPath (@{$localPathList}) {
+    my $sourcePath = $localPath->{copyFrom};
+    if (-e $sourcePath) {
+        print "\n*** Step 1/1: copying from $sourcePath\n";
+        system("$binDir/nix-store --dump $sourcePath | $binDir/nix-store --restore $targetPath") == 0
+            or die "cannot copy `$sourcePath' to `$targetPath'";
+        exit 0;
     }
 }
 
@@ -90,7 +154,7 @@ addToQueue $targetPath;
 
 sub isValidPath {
     my $p = shift;
-    return system("@bindir@/nix-store --check-validity '$p' 2> /dev/null") == 0;
+    return system("$binDir/nix-store --check-validity '$p' 2> /dev/null") == 0;
 }
 
 sub parseHash {
@@ -124,15 +188,13 @@ while ($queueFront < scalar @queue) {
                 my ($baseHashAlgo, $baseHash) = parseHash $patch->{baseHash};
                 my $format = "--base32";
                 $format = "" if $baseHashAlgo eq "md5";
-                my $hash = `@bindir@/nix-hash --type '$baseHashAlgo' $format "$patch->{basePath}"`;
+                my $hash = `$binDir/nix-hash --type '$baseHashAlgo' $format "$patch->{basePath}"`;
                 chomp $hash;
-#                print "  MY HASH is $hash\n";
                 if ($hash ne $baseHash) {
                     print LOGFILE "$$ rejecting $patch->{basePath}\n";
                     next;
                 }
             }
-#            print "  PATCH from $patch->{basePath}\n";
             addToQueue $patch->{basePath};
             addEdge $patch->{basePath}, $u, $patch->{size}, "patch", $patch;
         }
@@ -140,10 +202,12 @@ while ($queueFront < scalar @queue) {
         # Add NAR file edges to the start node.
         my $narFileList = $narFiles{$u};
         foreach my $narFile (@{$narFileList}) {
-#            print "  NAR from $narFile->{url}\n";
-            addEdge "start", $u, $narFile->{size}, "narfile", $narFile;
+            # !!! how to handle files whose size is not known in advance?
+            # For now, assume some arbitrary size (1 MB).
+            addEdge "start", $u, ($narFile->{size} || 1000000), "narfile", $narFile;
             if ($u eq $targetPath) {
-                print LOGFILE "$$ full-download-would-be $narFile->{size}\n";
+                my $size = $narFile->{size} || -1;
+                print LOGFILE "$$ full-download-would-be $size\n";
             }
         }
 
@@ -169,8 +233,6 @@ while (scalar @todo > 0) {
 
     my $u_ = $graph{$u};
 
-#    print "IN $u $u_->{d}\n";
-
     foreach my $edge (@{$u_->{edges}}) {
         my $v_ = $graph{$edge->{end}};
         if ($v_->{d} > $u_->{d} + $edge->{weight}) {
@@ -178,7 +240,6 @@ while (scalar @todo > 0) {
             # Store the edge; to edge->start is actually the
             # predecessor.
             $v_->{pred} = $edge; 
-#            print "  RELAX $edge->{end} $v_->{d}\n";
         }
     }
 }
@@ -200,20 +261,18 @@ while ($cur ne "start") {
 my $curStep = 1;
 my $maxStep = scalar @path;
 
-sub downloadFile {
-    my $url = shift;
-    my ($hashAlgo, $hash) = parseHash(shift);
+sub downloadFile { 
+    my $url = shift; 
     $ENV{"PRINT_PATH"} = 1;
     $ENV{"QUIET"} = 1;
-    $ENV{"NIX_HASH_ALGO"} = $hashAlgo;
-    my ($hash2, $path) = `@bindir@/nix-prefetch-url '$url' '$hash'`;
+    my ($hash, $path) = `$binDir/nix-prefetch-url '$url'`;
     die "download of `$url' failed" unless $? == 0;
-    chomp $hash2;
     chomp $path;
-    die "hash mismatch, expected $hash, got $hash2" if $hash ne $hash2;
     return $path;
 }
 
+my $finalNarHash;
+
 while (scalar @path > 0) {
     my $edge = pop @path;
     my $u = $edge->{start};
@@ -230,7 +289,7 @@ while (scalar @path > 0) {
             # as a base to one or more patches.  So turn the base path
             # into a NAR archive, to which we can apply the patch.
             print "  packing base path...\n";
-            system("@bindir@/nix-store --dump $v > $tmpNar") == 0
+            system("$binDir/nix-store --dump $v > $tmpNar") == 0
                 or die "cannot dump `$v'";
         }
     }
@@ -243,7 +302,7 @@ while (scalar @path > 0) {
 
         # Download the patch.
         print "  downloading patch...\n";
-        my $patchPath = downloadFile "$patch->{url}", "$patch->{hash}";
+        my $patchPath = downloadFile "$patch->{url}";
 
         # Apply the patch to the NAR archive produced in step 1 (for
         # the already present path) or a later step (for patch sequences).
@@ -258,20 +317,23 @@ while (scalar @path > 0) {
             # This was the last patch.  Unpack the final NAR archive
             # into the target path.
             print "  unpacking patched archive...\n";
-            system("@bindir@/nix-store --restore $v < $tmpNar2") == 0
+            system("$binDir/nix-store --restore $v < $tmpNar2") == 0
                 or die "cannot unpack $tmpNar2 into `$v'";
         }
+
+        $finalNarHash = $patch->{narHash};
     }
 
     elsif ($edge->{type} eq "narfile") {
         my $narFile = $edge->{info};
         print "downloading `$narFile->{url}' into `$v'\n";
 
-        print LOGFILE "$$ narfile $narFile->{url} $narFile->{size} $v\n";
+        my $size = $narFile->{size} || -1;
+        print LOGFILE "$$ narfile $narFile->{url} $size $v\n";
         
         # Download the archive.
         print "  downloading archive...\n";
-        my $narFilePath = downloadFile "$narFile->{url}", "$narFile->{hash}";
+        my $narFilePath = downloadFile "$narFile->{url}";
 
         if ($curStep < $maxStep) {
             # The archive will be used a base to a patch.
@@ -280,14 +342,39 @@ while (scalar @path > 0) {
         } else {
             # Unpack the archive into the target path.
             print "  unpacking archive...\n";
-            system("@bunzip2@ < '$narFilePath' | @bindir@/nix-store --restore '$v'") == 0
+            system("@bunzip2@ < '$narFilePath' | $binDir/nix-store --restore '$v'") == 0
                 or die "cannot unpack `$narFilePath' into `$v'";
         }
+
+        $finalNarHash = $narFile->{narHash};
     }
 
     $curStep++;
 }
 
 
+# Make sure that the hash declared in the manifest matches what we
+# downloaded and unpacked.
+
+if (defined $finalNarHash) {
+    my ($hashAlgo, $hash) = parseHash $finalNarHash;
+
+    # The hash in the manifest can be either in base-16 or base-32.
+    # Handle both.
+    my $extraFlag =
+        ($hashAlgo eq "sha256" && length($hash) != 64)
+        ? "--base32" : "";
+    
+    my $hash2 = `@bindir@/nix-hash --type $hashAlgo $extraFlag $targetPath`
+        or die "cannot compute hash of path `$targetPath'";
+    chomp $hash2;
+    
+    die "hash mismatch in downloaded path $targetPath; expected $hash, got $hash2"
+        if $hash ne $hash2;
+} else {
+    die "cannot check integrity of the downloaded path since its hash is not known";
+}
+
+
 print LOGFILE "$$ success\n";
 close LOGFILE;

scripts/find-runtime-roots.pl.in

@@ -56,3 +56,20 @@ sub lsof {
 
 readProc;
 lsof;
+
+
+sub readFile {
+    my $path = shift;
+    if (-e $path) {
+        if (open FILE, "$path") {
+            while (<FILE>) {
+                print;
+            }
+            close FILE;
+        }
+    }
+}
+
+# This is rather NixOS-specific, so it probably shouldn't be here.
+readFile "/proc/sys/kernel/modprobe";
+readFile "/proc/sys/kernel/fbsplash";

scripts/generate-patches.pl.in

@@ -4,6 +4,18 @@ use strict;
 use File::Temp qw(tempdir);
 use readmanifest;
 
+
+# Some patch generations options.
+
+# Max size of NAR archives to generate patches for.
+my $maxNarSize = $ENV{"NIX_MAX_NAR_SIZE"};
+$maxNarSize = 100 * 1024 * 1024 if !defined $maxNarSize;
+
+# If patch is bigger than this fraction of full archive, reject.
+my $maxPatchFraction = $ENV{"NIX_PATCH_FRACTION"};
+$maxPatchFraction = 0.60 if !defined $maxPatchFraction;
+
+
 die unless scalar @ARGV == 5;
 
 my $hashAlgo = "sha256";
@@ -22,23 +34,22 @@ print "TEMP = $tmpDir\n";
 #END { rmdir $tmpDir; }
 
 my %srcNarFiles;
+my %srcLocalPaths;
 my %srcPatches;
-my %srcSuccessors;
 
 my %dstNarFiles;
+my %dstLocalPaths;
 my %dstPatches;
-my %dstSuccessors;
 
 readManifest "$srcDir/MANIFEST",
-    \%srcNarFiles, \%srcPatches, \%srcSuccessors;
+    \%srcNarFiles, \%srcLocalPaths, \%srcPatches;
 
 readManifest "$dstDir/MANIFEST",
-    \%dstNarFiles, \%dstPatches, \%dstSuccessors;
+    \%dstNarFiles, \%dstLocalPaths, \%dstPatches;
 
 
 sub findOutputPaths {
     my $narFiles = shift;
-    my $successors = shift;
 
     my %outPaths;
     
@@ -63,10 +74,10 @@ sub findOutputPaths {
 }
 
 print "finding src output paths...\n";
-my %srcOutPaths = findOutputPaths \%srcNarFiles, \%srcSuccessors;
+my %srcOutPaths = findOutputPaths \%srcNarFiles;
 
 print "finding dst output paths...\n";
-my %dstOutPaths = findOutputPaths \%dstNarFiles, \%dstSuccessors;
+my %dstOutPaths = findOutputPaths \%dstNarFiles;
 
 
 sub getNameVersion {
@@ -277,8 +288,6 @@ foreach my $p (keys %dstOutPaths) {
         my $srcNarBz2 = getNarBz2 \%srcNarFiles, $closest;
         my $dstNarBz2 = getNarBz2 \%dstNarFiles, $p;
 
-        my $maxNarSize = 150 * 1024 * 1024;
-
         system("@bunzip2@ < $srcNarBz2 > $tmpDir/A") == 0
             or die "cannot unpack $srcNarBz2";
 
@@ -310,16 +319,21 @@ foreach my $p (keys %dstOutPaths) {
         my $narDiffSize = (stat "$tmpDir/DIFF")[7];
         my $dstNarBz2Size = (stat $dstNarBz2)[7];
 
+        print "    size $narDiffSize; full size $dstNarBz2Size\n";
+        
         if ($narDiffSize >= $dstNarBz2Size) {
             print "    rejecting; patch bigger than full archive\n";
             next;
         }
     
+        if ($narDiffSize / $dstNarBz2Size >= $maxPatchFraction) {
+            print "    rejecting; patch too large relative to full archive\n";
+            next;
+        }
+    
         my $finalName =
             "$narDiffHash.nar-bsdiff";
 
-        print "    size $narDiffSize; full size $dstNarBz2Size\n";
-        
         if (-e "$patchesDir/$finalName") {
             print "    not copying, already exists\n";
         }
@@ -348,11 +362,22 @@ foreach my $p (keys %dstOutPaths) {
 # patches that produce either paths in the destination or paths that
 # can be used as the base for other useful patches).
 
+print "propagating patches...\n";
+
 my $changed;
 do {
     # !!! we repeat this to reach the transitive closure; inefficient
     $changed = 0;
 
+    print "loop\n";
+
+    my %dstBasePaths;
+    foreach my $q (keys %dstPatches) {
+	foreach my $patch (@{$dstPatches{$q}}) {
+	    $dstBasePaths{$patch->{basePath}} = 1;
+	}
+    }
+
     foreach my $p (keys %srcPatches) {
         my $patchList = $srcPatches{$p};
 
@@ -360,22 +385,18 @@ do {
 
         # Is path $p included in the destination?  If so, include
         # patches that produce it.
-        $include = 1 if (defined $dstNarFiles{$p});
+        $include = 1 if defined $dstNarFiles{$p};
 
         # Is path $p a path that serves as a base for paths in the
         # destination?  If so, include patches that produce it.
-        foreach my $q (keys %dstPatches) {
-            foreach my $patch (@{$dstPatches{$q}}) {
-                # !!! check baseHash
-                $include = 1 if ($p eq $patch->{basePath});
-            }
-        }
+	# !!! check baseHash
+        $include = 1 if defined $dstBasePaths{$p};
 
         if ($include) {
             foreach my $patch (@{$patchList}) {
                 $changed = 1 if addPatch \%dstPatches, $p, $patch;
             }
-        }            
+        }
         
     }
     
@@ -384,4 +405,4 @@ do {
 
 # Rewrite the manifest of the destination (with the new patches).
 writeManifest "$dstDir/MANIFEST",
-    \%dstNarFiles, \%dstPatches, \%dstSuccessors;
+    \%dstNarFiles, \%dstPatches;

scripts/maintenance/gc-releases.pl

@@ -7,12 +7,12 @@ use readcache;
 
 # Read the manifests.
 my %narFiles;
+my %localPaths;
 my %patches;
-my %successors;
 
 foreach my $manifest (@ARGV) {
     print STDERR "loading $manifest\n";
-    if (readManifest($manifest, \%narFiles, \%patches, \%successors, 1) < 3) {
+    if (readManifest($manifest, \%narFiles, \%localPaths, \%patches, 1) < 3) {
 #        die "manifest `$manifest' is too old (i.e., for Nix <= 0.7)\n";
     }
 }

scripts/maintenance/readcache.pm

@@ -15,7 +15,7 @@ sub readDir {
 }
 
 readDir "/data/webserver/dist/nix-cache";
-readDir "/data/webserver/dist/test";
+readDir "/data/webserver/dist/test-cache";
 readDir "/data/webserver/dist/patches";
 
 print STDERR scalar (keys %archives), "\n";

scripts/maintenance/shrink-manifest.pl

@@ -6,12 +6,12 @@ use readcache;
 
 
 my %allNarFiles;
+my %allLocalPaths;
 my %allPatches;
-my %allSuccessors;
 
 foreach my $manifest (glob "/data/webserver/dist/*/*/MANIFEST") {
     print STDERR "loading $manifest\n";
-    readManifest($manifest, \%allNarFiles, \%allPatches, \%allSuccessors, 1);
+    readManifest($manifest, \%allNarFiles, \%allLocalPaths, \%allPatches, 1);
 }
 
 
@@ -22,9 +22,8 @@ foreach my $manifest (@ARGV) {
 
     my %narFiles;
     my %patches;
-    my %successors;
 
-    if (readManifest($manifest, \%narFiles, \%patches, \%successors, 1) < 3) {
+    if (readManifest($manifest, \%narFiles, \%patches, 1) < 3) {
         print STDERR "manifest `$manifest' is too old (i.e., for Nix <= 0.7)\n";
 	next;
     }

scripts/nix-build.in

@@ -2,6 +2,8 @@
 
 use strict;
 
+my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
+
 
 my $addDrvLink = 0;
 my $addOutLink = 1;
@@ -9,6 +11,8 @@ my $addOutLink = 1;
 my $outLink;
 my $drvLink;
 
+my $dryRun = 0;
+
 my @instArgs = ();
 my @buildArgs = ();
 my @exprs = ();
@@ -56,7 +60,7 @@ EOF
     }
 
     elsif ($arg eq "--no-out-link" or $arg eq "--no-link") {
-        $addOutLink = 1;
+        $addOutLink = 0;
     }
 
     elsif ($arg eq "--drv-link") {
@@ -73,16 +77,41 @@ EOF
 
     elsif ($arg eq "--attr" or $arg eq "-A") {
         $n++;
-        die "$0: `--attr' requires an argument\n" unless $n < scalar @ARGV;
+        die "$0: `$arg' requires an argument\n" unless $n < scalar @ARGV;
         push @instArgs, ("--attr", $ARGV[$n]);
     }
 
-    elsif ($arg eq "--arg") {
-        die "$0: `--arg' requires two arguments\n" unless $n + 2 < scalar @ARGV;
-        push @instArgs, ("--arg", $ARGV[$n + 1], $ARGV[$n + 2]);
+    elsif ($arg eq "--arg" || $arg eq "--argstr") {
+        die "$0: `$arg' requires two arguments\n" unless $n + 2 < scalar @ARGV;
+        push @instArgs, ($arg, $ARGV[$n + 1], $ARGV[$n + 2]);
         $n += 2;
     }
 
+    elsif ($arg eq "--log-type") {
+        $n++;
+        die "$0: `$arg' requires an argument\n" unless $n < scalar @ARGV;
+        push @instArgs, ($arg, $ARGV[$n]);
+        push @buildArgs, ($arg, $ARGV[$n]);
+    }
+
+    elsif ($arg eq "--option") {
+        die "$0: `$arg' requires two arguments\n" unless $n + 2 < scalar @ARGV;
+        push @instArgs, ($arg, $ARGV[$n + 1], $ARGV[$n + 2]);
+        push @buildArgs, ($arg, $ARGV[$n + 1], $ARGV[$n + 2]);
+        $n += 2;
+    }
+
+    elsif ($arg eq "--max-jobs" or $arg eq "-j" or $arg eq "--max-silent-time" or $arg eq "--log-type") {
+        $n++;
+        die "$0: `$arg' requires an argument\n" unless $n < scalar @ARGV;
+        push @buildArgs, ($arg, $ARGV[$n]);
+    }
+
+    elsif ($arg eq "--dry-run") {
+        push @buildArgs, "--dry-run";
+        $dryRun = 1;
+    }
+    
     elsif (substr($arg, 0, 1) eq "-") {
         push @buildArgs, $arg;
     }
@@ -111,22 +140,32 @@ foreach my $expr (@exprs) {
     # Instantiate.
     my @drvPaths;
     # !!! would prefer the perl 5.8.0 pipe open feature here.
-    my $pid = open(DRVPATHS, "-|") || exec "@bindir@/nix-instantiate", "--add-root", $drvLink, "--indirect", @instArgs, $expr;
+    my $pid = open(DRVPATHS, "-|") || exec "$binDir/nix-instantiate", "--add-root", $drvLink, "--indirect", @instArgs, $expr;
     while (<DRVPATHS>) {chomp; push @drvPaths, $_;}
-    close DRVPATHS or exit 1;
+    if (!close DRVPATHS) {
+        die "nix-instantiate killed by signal " . ($? & 127) . "\n" if ($? & 127);
+        exit 1;
+    }
 
     foreach my $drvPath (@drvPaths) {
-        my $target = readlink $drvPath;
+        my $target = readlink $drvPath or die "cannot read symlink `$drvPath'";
         print STDERR "store derivation is $target\n";
     }
 
     # Build.
-    my $outPaths = `@bindir@/nix-store --add-root "$outLink" --indirect -rv @buildArgs @drvPaths`;
-    my @outPaths = split ' ', $outPaths;
-    
-    foreach my $outPath (@outPaths) {
-        my $target = readlink $outPath;
-        print "$target\n";
+    my @outPaths;
+    $pid = open(OUTPATHS, "-|") || exec "$binDir/nix-store", "--add-root", $outLink, "--indirect", "-rv",
+        @buildArgs, @drvPaths;
+    while (<OUTPATHS>) {chomp; push @outPaths, $_;}
+    if (!close OUTPATHS) {
+        die "nix-store killed by signal " . ($? & 127) . "\n" if ($? & 127);
+        exit 1;
     }
 
+    next if $dryRun;
+
+    foreach my $outPath (@outPaths) {
+        my $target = readlink $outPath or die "cannot read symlink `$outPath'";
+        print "$target\n";
+    }
 }

scripts/nix-channel.in

@@ -2,16 +2,24 @@
 
 use strict;
 
-my $rootsDir = "@localstatedir@/nix/gcroots/channels";
+my $rootsDir = "@localstatedir@/nix/gcroots";
 
 my $stateDir = $ENV{"NIX_STATE_DIR"};
 $stateDir = "@localstatedir@/nix" unless defined $stateDir;
 
 
+# Turn on caching in nix-prefetch-url.
+my $channelCache = "$stateDir/channel-cache";
+mkdir $channelCache, 0755 unless -e $channelCache;
+$ENV{'NIX_DOWNLOAD_CACHE'} = $channelCache if -W $channelCache;
+
+
 # Figure out the name of the `.nix-channels' file to use.
 my $home = $ENV{"HOME"};
 die '$HOME not set' unless defined $home;
 my $channelsList = "$home/.nix-channels";
+
+my $nixDefExpr = "$home/.nix-defexpr";
     
 
 my @channels;
@@ -70,61 +78,70 @@ sub removeChannel {
 sub update {
     readChannels;
 
-    # Get rid of all the old substitutes.
-    system("@bindir@/nix-store", "--clear-substitutes") == 0
-        or die "cannot clear substitutes";
+    # Do we have write permission to the manifests directory?  If not,
+    # then just skip pulling the manifest and just download the Nix
+    # expressions.  If the user is a non-privileged user in a
+    # multi-user Nix installation, he at least gets installation from
+    # source.
+    if (-W "$stateDir/manifests") {
 
-    # Remove all the old manifests.
-    for my $manifest (glob "$stateDir/manifests/*.nixmanifest") {
-        unlink $manifest or die "cannot remove `$manifest': $!";
-    }
+        # Remove all the old manifests.
+        for my $manifest (glob "$stateDir/manifests/*.nixmanifest") {
+            unlink $manifest or die "cannot remove `$manifest': $!";
+        }
+
+        # Pull cache manifests.
+        foreach my $url (@channels) {
+            #print "pulling cache manifest from `$url'\n";
+            system("@bindir@/nix-pull", "--skip-wrong-store", "$url/MANIFEST") == 0
+                or die "cannot pull cache manifest from `$url'";
+        }
 
-    # Pull cache manifests.
-    foreach my $url (@channels) {
-        print "pulling cache manifest from `$url'\n";
-        system("@bindir@/nix-pull", "--skip-wrong-store", "$url/MANIFEST") == 0
-            or die "cannot pull cache manifest from `$url'";
     }
 
     # Create a Nix expression that fetches and unpacks the channel Nix
     # expressions.
 
-    my $nixExpr = "[";
+    my $inputs = "[";
     foreach my $url (@channels) {
+        $url =~ /\/([^\/]+)\/?$/;
+        my $channelName = $1;
+        $channelName = "unnamed" unless defined $channelName;
+
         my $fullURL = "$url/nixexprs.tar.bz2";
+        print "downloading Nix expressions from `$fullURL'...\n";
         $ENV{"PRINT_PATH"} = 1;
-        my ($hash, $path) = `@bindir@/nix-prefetch-url '$fullURL' 2> /dev/null`;
+        $ENV{"QUIET"} = 1;
+        my ($hash, $path) = `@bindir@/nix-prefetch-url '$fullURL'`;
         die "cannot fetch `$fullURL'" if $? != 0;
         chomp $path;
-        $nixExpr .= $path . " ";
+        $inputs .= '"' . $channelName . '"' . " " . $path . " ";
     }
-    $nixExpr .= "]";
-
-    $nixExpr =
-        "(import @datadir@/nix/corepkgs/channels/unpack.nix) " .
-        "{inputs = $nixExpr; system = \"@system@\";}";
+    $inputs .= "]";
 
     # Figure out a name for the GC root.
     my $userName = getpwuid($<);
     die "who ARE you? go away" unless defined $userName;
 
-    my $rootFile = "$rootsDir/$userName";
+    my $rootFile = "$rootsDir/per-user/$userName/channels";
     
-    # Instantiate the Nix expression.
-    my $storeExpr = `echo '$nixExpr' | @bindir@/nix-instantiate --add-root '$rootFile'.tmp -`
-        or die "cannot instantiate Nix expression";
-    chomp $storeExpr;
-
-    # Build the resulting derivation.
-    my $outPath = `@bindir@/nix-store --add-root '$rootFile' -r '$storeExpr'`
-        or die "cannot realise store expression";
+    # Build the Nix expression.
+    print "unpacking channel Nix expressions...\n";
+    my $outPath = `\\
+        @bindir@/nix-build --out-link '$rootFile' --drv-link '$rootFile'.tmp \\
+        @datadir@/nix/corepkgs/channels/unpack.nix \\
+        --argstr system @system@ --arg inputs '$inputs'`
+        or die "cannot unpack the channels";
     chomp $outPath;
 
     unlink "$rootFile.tmp";
 
-    # Make it the default Nix expression for `nix-env'.
-    system("@bindir@/nix-env", "--import", "$outPath") == 0
-         or die "cannot pull set default Nix expression to `$outPath'";
+    # Make the channels appear in nix-env.
+    unlink $nixDefExpr if -l $nixDefExpr; # old-skool ~/.nix-defexpr
+    mkdir $nixDefExpr or die "cannot create directory `$nixDefExpr'" if !-e $nixDefExpr;
+    my $channelLink = "$nixDefExpr/channels";
+    unlink $channelLink; # !!! not atomic
+    symlink($outPath, $channelLink) or die "cannot symlink `$channelLink' to `$outPath'";
 }
 
 

scripts/nix-collect-garbage.in

@@ -4,6 +4,8 @@ use strict;
 
 my $profilesDir = "@localstatedir@/nix/profiles";
 
+my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
+
 
 # Process the command line arguments.
 my @args = ();
@@ -21,22 +23,31 @@ for my $arg (@ARGV) {
 # If `-d' was specified, remove all old generations of all profiles.
 # Of course, this makes rollbacks to before this point in time
 # impossible.
-if ($removeOld) {
 
-    opendir DIR, $profilesDir or die;
+sub removeOldGenerations;
+sub removeOldGenerations {
+    my $dir = shift;
 
-    foreach my $name (sort (readdir DIR)) {
-        $name = $profilesDir . "/" . $name;
+    my $dh;
+    opendir $dh, $dir or die;
+
+    foreach my $name (sort (readdir $dh)) {
+        next if $name eq "." || $name eq "..";
+        $name = $dir . "/" . $name;
         if (-l $name && (readlink($name) =~ /link/)) {
             print STDERR "removing old generations of profile $name\n";
-            system("@bindir@/nix-env", "-p", $name, "--delete-generations", "old");
+            system("$binDir/nix-env", "-p", $name, "--delete-generations", "old");
+        }
+        elsif (! -l $name && -d $name) {
+            removeOldGenerations $name;
         }
     }
     
-    closedir DIR or die;
-    
+    closedir $dh or die;
 }
 
+removeOldGenerations $profilesDir if $removeOld;
+
 
 # Run the actual garbage collector.
-exec "@bindir@/nix-store", "--gc", @args;
+exec "$binDir/nix-store", "--gc", @args;

scripts/nix-copy-closure.in

@@ -0,0 +1,131 @@
+#! @perl@ -w
+
+my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
+
+
+if (scalar @ARGV < 1) {
+    print STDERR <<EOF
+Usage: nix-copy-closure [--from | --to] HOSTNAME [--sign] [--gzip] PATHS...
+EOF
+    ;
+    exit 1;
+}
+
+
+# Get the target host.
+my $sshHost;
+my @sshOpts = split ' ', ($ENV{"NIX_SSHOPTS"} or "");
+
+my $sign = 0;
+
+my $compressor = "cat";
+my $decompressor = "cat";
+
+my $toMode = 1;
+
+
+# !!! Copied from nix-pack-closure, should put this in a module.
+my @storePaths = ();
+
+while (@ARGV) {
+    my $arg = shift @ARGV;
+    
+    if ($arg eq "--sign") {
+        $sign = 1;
+    }
+    elsif ($arg eq "--gzip") {
+        $compressor = "gzip";
+        $decompressor = "gunzip";
+    }
+    elsif ($arg eq "--from") {
+        $toMode = 0;
+    }
+    elsif ($arg eq "--to") {
+        $toMode = 1;
+    }
+    elsif (!defined $sshHost) {
+        $sshHost = $arg;
+    }
+    else {
+        push @storePaths, $arg;
+    }
+}
+
+
+if ($toMode) { # Copy TO the remote machine.
+
+    my @allStorePaths;
+
+    # Get the closure of this path.
+    my $pid = open(READ, "$binDir/nix-store --query --requisites @storePaths|") or die;
+    
+    while (<READ>) {
+        chomp;
+        die "bad: $_" unless /^\//;
+        push @allStorePaths, $_;
+    }
+
+    close READ or die "nix-store failed: $?";
+
+
+    # Ask the remote host which paths are invalid.
+    open(READ, "ssh @sshOpts $sshHost nix-store --check-validity --print-invalid @allStorePaths|");
+    my @missing = ();
+    while (<READ>) {
+        chomp;
+        print STDERR "target machine needs $_\n";
+        push @missing, $_;
+    }
+    close READ or die;
+
+
+    # Export the store paths and import them on the remote machine.
+    if (scalar @missing > 0) {
+        my $extraOpts = "";
+        $extraOpts .= "--sign" if $sign == 1;
+        system("nix-store --export $extraOpts @missing | $compressor | ssh @sshOpts $sshHost '$decompressor | nix-store --import'") == 0
+            or die "copying store paths to remote machine `$sshHost' failed: $?";
+    }
+
+}
+
+
+else { # Copy FROM the remote machine.
+
+    # Query the closure of the given store paths on the remote
+    # machine.  Paths are assumed to be store paths; there is no
+    # resolution (following of symlinks).
+    my $pid = open(READ,
+        "ssh @sshOpts $sshHost nix-store --query --requisites @storePaths|") or die;
+    
+    my @allStorePaths;
+
+    while (<READ>) {
+        chomp;
+        die "bad: $_" unless /^\//;
+        push @allStorePaths, $_;
+    }
+
+    close READ or die "nix-store on remote machine `$sshHost' failed: $?";
+
+
+    # What paths are already valid locally?
+    open(READ, "@bindir@/nix-store --check-validity --print-invalid @allStorePaths|");
+    my @missing = ();
+    while (<READ>) {
+        chomp;
+        print STDERR "local machine needs $_\n";
+        push @missing, $_;
+    }
+    close READ or die;
+    
+
+    # Export the store paths on the remote machine and import them on locally.
+    if (scalar @missing > 0) {
+        my $extraOpts = "";
+        $extraOpts .= "--sign" if $sign == 1;
+        system("ssh @sshOpts $sshHost 'nix-store --export $extraOpts @missing | $compressor' | $decompressor | @bindir@/nix-store --import") == 0
+            or die "copying store paths to remote machine `$sshHost' failed: $?";
+    }
+
+}

scripts/nix-http-export.cgi.in

@@ -0,0 +1,51 @@
+#! /bin/sh
+
+export HOME=/tmp
+export NIX_REMOTE=daemon
+
+TMP_DIR="${TMP_DIR:-/tmp/nix-export}"
+
+@coreutils@/mkdir -p "$TMP_DIR" || true
+@coreutils@/chmod a+r "$TMP_DIR"
+
+needed_path="?$QUERY_STRING"
+needed_path="${needed_path#*[?&]needed_path=}"
+needed_path="${needed_path%%&*}"
+#needed_path="$(echo $needed_path  | ./unhttp)"
+needed_path="${needed_path//%2B/+}"
+needed_path="${needed_path//%3D/=}"
+
+echo needed_path: "$needed_path" >&2
+
+NIX_STORE="${NIX_STORE_DIR:-/nix/store}"
+
+echo NIX_STORE: "${NIX_STORE}" >&2
+
+full_path="${NIX_STORE}"/"$needed_path"
+
+if [ "$needed_path" != "${needed_path%.drv}" ]; then
+	echo "Status: 403 You should create the derivation file yourself"
+	echo "Content-Type: text/plain"
+	echo
+	echo "Refusing to disclose derivation contents"
+	exit
+fi
+
+if @bindir@/nix-store --check-validity "$full_path"; then
+	if ! [ -e nix-export/"$needed_path".nar.gz ]; then
+		@bindir@/nix-store --export "$full_path" | @gzip@ > "$TMP_DIR"/"$needed_path".nar.gz
+		@coreutils@/ln -fs  "$TMP_DIR"/"$needed_path".nar.gz nix-export/"$needed_path".nar.gz 
+	fi;
+	echo "Status: 301 Moved"
+	echo "Location: nix-export/"$needed_path".nar.gz"
+	echo
+else 
+	echo "Status: 404 No such path found"
+	echo "Content-Type: text/plain"
+	echo
+	echo "Path not found:"
+	echo "$needed_path"
+	echo "checked:"
+	echo "$full_path"
+fi
+

scripts/nix-install-package.in

@@ -3,6 +3,8 @@
 use strict;
 use File::Temp qw(tempdir);
 
+my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
+
 
 sub usageError {
     print STDERR <<EOF;
@@ -13,7 +15,7 @@ downloading it from URL.
 
 Flags:
   --profile / -p LINK: install into the specified profile
-  --non-interactive: don't run inside a new terminal XXX
+  --non-interactive: don't run inside a new terminal
 EOF
     ; # '
     exit 1;
@@ -59,7 +61,7 @@ if ($interactive && !defined $ENV{"NIX_HAVE_TERMINAL"}) {
     $ENV{"NIX_HAVE_TERMINAL"} = "1";
     $ENV{"LD_LIBRARY_PATH"} = "";
     foreach my $term ("xterm", "konsole", "gnome-terminal", "xterm") {
-        exec($term, "-e", "@bindir@/nix-install-package", @ARGV);
+        exec($term, "-e", "$binDir/nix-install-package", @ARGV);
     }
     die "cannot execute `xterm'";
 }
@@ -121,13 +123,18 @@ if ($interactive) {
 }
 
 
+# Store the manifest in the temporary directory so that we don't
+# pollute /nix/var/nix/manifests.
+$ENV{NIX_MANIFESTS_DIR} = $tmpDir;
+
+
 print "\nPulling manifests...\n";
-system("@bindir@/nix-pull", $manifestURL) == 0
+system("$binDir/nix-pull", $manifestURL) == 0
     or barf "nix-pull failed: $?";
 
 
 print "\nInstalling package...\n";
-system("@bindir@/nix-env", "--install", $outPath, "--force-name", $drvName, @extraNixEnvArgs) == 0
+system("$binDir/nix-env", "--install", $outPath, "--force-name", $drvName, @extraNixEnvArgs) == 0
     or barf "nix-env failed: $?";
 
 

scripts/nix-pack-closure.in

@@ -1,65 +0,0 @@
-#! @perl@ -w
-
-# This tool computes the closure of a path (using "nix-store --query
-# --requisites") and puts the contents of each path in the closure in
-# a big NAR archive that can be installed on another Nix installation
-# using "nix-unpack-closure".
-
-# TODO: make this program "streamy", i.e., don't use a temporary
-# directory.
-
-use strict;
-use File::Temp qw(tempdir);
-
-my $binDir = $ENV{"NIX_BIN_DIR"};
-$binDir = "@bindir@" unless defined $binDir;
-
-my $tmpDir = tempdir("nix-pack-closure.XXXXXX", CLEANUP => 1, TMPDIR => 1)
-    or die "cannot create a temporary directory";
-
-mkdir "$tmpDir/contents", 0777 or die;
-mkdir "$tmpDir/references", 0777 or die;
-mkdir "$tmpDir/derivers", 0777 or die;
-
-
-
-my %storePaths;
-
-
-while (@ARGV) {
-    my $storePath = shift @ARGV;
-
-    # Get the closure of this path.
-    my $pid = open(READ,
-        "$binDir/nix-store --query --requisites '$storePath'|") or die;
-    
-    while (<READ>) {
-        chomp;
-        die "bad: $_" unless /^\//;
-        $storePaths{$_} = "";
-    }
-
-    close READ or die "nix-store failed: $?";
-}
-
-
-foreach my $storePath (sort(keys %storePaths)) {
-    print STDERR "packing `$storePath'...\n";
-
-    $storePath =~ /\/([^\/]+)$/;
-    my $name = $1;
-
-    system("$binDir/nix-store --dump '$storePath' > $tmpDir/contents/$name") == 0
-        or die "nix-store --dump failed on `$storePath': $?";
-
-    system("$binDir/nix-store --query --references '$storePath' > $tmpDir/references/$name") == 0
-        or die "nix-store --query --references failed on `$storePath': $?";
-
-    system("$binDir/nix-store --query --deriver '$storePath' > $tmpDir/derivers/$name") == 0
-        or die "nix-store --query --deriver failed on `$storePath': $?";
-}
-
-
-# Write a NAR archive of everything to standard output.
-system("nix-store --dump '$tmpDir'") == 0
-    or die "nix-store --dump failed";

scripts/nix-prefetch-url.in

@@ -3,15 +3,12 @@
 url=$1
 expHash=$2
 
-# to prevent doing more than 1 chroot
-unset NIX_ROOT
-
 # needed to make it work on NixOS
 export PATH=$PATH:@coreutils@
 
 hashType=$NIX_HASH_ALGO
 if test -z "$hashType"; then
-    hashType=md5
+    hashType=sha256
 fi
 
 hashFormat=
@@ -39,29 +36,116 @@ if test -n "$expHash"; then
 fi
 
 
+mkTempDir() {
+    if test -n "$tmpPath"; then return; fi
+    local i=0
+    while true; do
+        if test -z "$TMPDIR"; then TMPDIR=/tmp; fi
+        tmpPath=$TMPDIR/nix-prefetch-url-$$-$i
+        if mkdir "$tmpPath"; then break; fi
+        # !!! to bad we can't check for ENOENT in mkdir, so this check
+        # is slightly racy (it bombs out if somebody just removed
+        # $tmpPath...).
+        if ! test -e "$tmpPath"; then exit 1; fi
+        i=$((i + 1))
+    done
+    trap removeTempDir EXIT SIGINT SIGQUIT
+}
+
+removeTempDir() {
+    if test -n "$tmpPath"; then
+        rm -rf "$tmpPath" || true
+    fi
+}
+
+
+doDownload() {
+    @curl@ $cacheFlags --fail --location --max-redirs 20 --disable-epsv \
+        --cookie-jar $tmpPath/cookies "$url" -o $tmpFile
+}
+
+
+# Hack to support the mirror:// scheme from Nixpkgs.
+if test "${url:0:9}" = "mirror://"; then
+    if test -z "$NIXPKGS_ALL"; then
+        echo "Resolving mirror:// URLs requires Nixpkgs.  Please point \$NIXPKGS_ALL at a Nixpkgs tree." >&2
+        exit 1
+    fi
+
+    mkTempDir
+    nix-build "$NIXPKGS_ALL" -A resolveMirrorURLs --argstr url "$url" -o $tmpPath/urls > /dev/null
+
+    expanded=($(cat $tmpPath/urls))
+    if test "${#expanded[*]}" = 0; then
+        echo "$0: cannot resolve $url." >&2
+        exit 1
+    fi
+
+    echo "$url expands to ${expanded[*]} (using ${expanded[0]})" >&2
+    url="${expanded[0]}"
+fi
+
+
 # If we don't know the hash or a file with that hash doesn't exist,
 # download the file and add it to the store.
 if test -z "$finalPath"; then
 
-    tmpPath=/tmp/nix-prefetch-url-$$ # !!! security?
+    mkTempDir
     tmpFile=$tmpPath/$name
-    mkdir $tmpPath
+
+    # Optionally do timestamp-based caching of the download.
+    # Actually, the only thing that we cache in $NIX_DOWNLOAD_CACHE is
+    # the hash and the timestamp of the file at $url.  The caching of
+    # the file *contents* is done in Nix store, where it can be
+    # garbage-collected independently.
+    if test -n "$NIX_DOWNLOAD_CACHE"; then
+        echo -n "$url" > $tmpPath/url
+        urlHash=$(@bindir@/nix-hash --type sha256 --base32 --flat $tmpPath/url)
+        echo "$url" > "$NIX_DOWNLOAD_CACHE/$urlHash.url"
+        cachedHashFN="$NIX_DOWNLOAD_CACHE/$urlHash.$hashType"
+        cachedTimestampFN="$NIX_DOWNLOAD_CACHE/$urlHash.stamp"
+        cacheFlags="--remote-time"
+        if test -e "$cachedTimestampFN" -a -e "$cachedHashFN"; then
+            # Only download the file if it is newer than the cached version.
+            cacheFlags="$cacheFlags --time-cond $cachedTimestampFN"
+        fi
+    fi
 
     # Perform the download.
-    @curl@ --fail --location --max-redirs 20 "$url" > $tmpFile
+    doDownload
 
-    # Compute the hash.
-    hash=$(@bindir@/nix-hash --type "$hashType" $hashFormat --flat $tmpFile)
-    if ! test -n "$QUIET"; then echo "hash is $hash" >&2; fi
+    if test -n "$NIX_DOWNLOAD_CACHE" -a ! -e $tmpFile; then
+        # Curl didn't create $tmpFile, so apparently there's no newer
+        # file on the server.
+        hash=$(cat $cachedHashFN)
+        finalPath=$(@bindir@/nix-store --print-fixed-path "$hashType" "$hash" "$name") 
+        if ! @bindir@/nix-store --check-validity "$finalPath" 2> /dev/null; then
+            echo "cached contents of \`$url' disappeared, redownloading..." >&2
+            finalPath=
+            cacheFlags="--remote-time"
+            doDownload
+        fi
+    fi
 
-    # Add the downloaded file to the Nix store.
-    finalPath=$(@bindir@/nix-store --add-fixed "$hashType" $tmpFile)
+    if test -z "$finalPath"; then
 
-    if test -n "$tmpPath"; then rm -rf $tmpPath || true; fi
+        # Compute the hash.
+        hash=$(@bindir@/nix-hash --type "$hashType" $hashFormat --flat $tmpFile)
+        if ! test -n "$QUIET"; then echo "hash is $hash" >&2; fi
 
-    if test -n "$expHash" -a "$expHash" != "$hash"; then
-        echo "hash mismatch for URL \`$url'"
-        exit 1
+        if test -n "$NIX_DOWNLOAD_CACHE"; then
+            echo $hash > $cachedHashFN
+            touch -r $tmpFile $cachedTimestampFN
+        fi
+
+        # Add the downloaded file to the Nix store.
+        finalPath=$(@bindir@/nix-store --add-fixed "$hashType" $tmpFile)
+
+        if test -n "$expHash" -a "$expHash" != "$hash"; then
+            echo "hash mismatch for URL \`$url'" >&2
+            exit 1
+        fi
+        
     fi
 fi
 

scripts/nix-profile.sh.in

@@ -7,5 +7,12 @@ if test -n "$HOME"; then
         @coreutils@/ln -s "$_NIX_DEF_LINK" "$NIX_LINK"
     fi
 
-    export PATH=$NIX_LINK/bin:@prefix@/bin:$PATH
+    export PATH=$NIX_LINK/bin:$PATH
+fi
+
+# This is a quick hack to make fontconfig-based packages in Nixpkgs
+# work out of the box on non-NixOS systems.  Of course, we should
+# really fix fontconfig...
+if test -z "$FONTCONFIG_FILE" -a -e /etc/fonts/fonts.conf; then
+    export FONTCONFIG_FILE=/etc/fonts/fonts.conf
 fi

scripts/nix-pull.in

@@ -7,19 +7,11 @@ use readmanifest;
 my $tmpDir = tempdir("nix-pull.XXXXXX", CLEANUP => 1, TMPDIR => 1)
     or die "cannot create a temporary directory";
 
-my $manifest = "$tmpDir/manifest";
-
-my $binDir = $ENV{"NIX_BIN_DIR"};
-$binDir = "@bindir@" unless defined $binDir;
-
-my $libexecDir = $ENV{"NIX_LIBEXEC_DIR"};
-$libexecDir = "@libexecdir@" unless defined $libexecDir;
-
-my $stateDir = $ENV{"NIX_STATE_DIR"};
-$stateDir = "@localstatedir@/nix" unless defined $stateDir;
-
-my $storeDir = $ENV{"NIX_STORE_DIR"};
-$storeDir = "@storedir@" unless defined $storeDir;
+my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
+my $libexecDir = ($ENV{"NIX_LIBEXEC_DIR"} or "@libexecdir@");
+my $storeDir = ($ENV{"NIX_STORE_DIR"} or "@storedir@");
+my $stateDir = ($ENV{"NIX_STATE_DIR"} or "@localstatedir@/nix");
+my $manifestDir = ($ENV{"NIX_MANIFESTS_DIR"} or "$stateDir/manifests");
 
 
 # Prevent access problems in shared-stored installations.
@@ -28,25 +20,55 @@ umask 0022;
 
 # Process the URLs specified on the command line.
 my %narFiles;
+my %localPaths;
 my %patches;
-my %successors;
 
 my $skipWrongStore = 0;
 
+sub downloadFile {
+    my $url = shift;
+    $ENV{"PRINT_PATH"} = 1;
+    $ENV{"QUIET"} = 1;
+    my ($dummy, $path) = `$binDir/nix-prefetch-url '$url'`;
+    die "cannot fetch `$url'" if $? != 0;
+    die "nix-prefetch-url did not return a path" unless defined $path;
+    chomp $path;
+    return $path;
+}
+
 sub processURL {
     my $url = shift;
 
     $url =~ s/\/$//;
-    print "obtaining list of Nix archives at $url...\n";
 
-    system("@curl@ --fail --silent --show-error --location --max-redirs 20 " .
-           "'$url' > '$manifest'") == 0
-           or die "curl failed: $?";
+    my $manifest;
 
-    if (readManifest($manifest, \%narFiles, \%patches, \%successors) < 3) {
-        die "manifest `$url' is too old (i.e., for Nix <= 0.7)\n";
+    # First see if a bzipped manifest is available.
+    if (system("@curl@ --fail --silent --head '$url'.bz2 > /dev/null") == 0) {
+        print "obtaining list of Nix archives at `$url.bz2'...\n";
+        my $bzipped = downloadFile "$url.bz2";
+
+        $manifest = "$tmpDir/MANIFEST";
+
+        system("@bunzip2@ < $bzipped > $manifest") == 0
+            or die "cannot decompress manifest";
+
+        $manifest = (`$binDir/nix-store --add $manifest`
+                     or die "cannot copy $manifest to the store");
+        chomp $manifest;
     }
 
+    # Otherwise, just get the uncompressed manifest.
+    else {
+        print "obtaining list of Nix archives at `$url'...\n";
+        $manifest = downloadFile $url;
+    }
+
+    my $version = readManifest($manifest, \%narFiles, \%localPaths, \%patches);
+    
+    die "`$url' is not a manifest or it is too old (i.e., for Nix <= 0.7)\n" if $version < 3;
+    die "manifest `$url' is too new\n" if $version >= 5;
+
     if ($skipWrongStore) {
         foreach my $path (keys %narFiles) {
             if (substr($path, 0, length($storeDir) + 1) ne "$storeDir/") {
@@ -65,10 +87,10 @@ sub processURL {
         or die "cannot hash `$manifest'";
     chomp $hash;
     
-    my $finalPath = "$stateDir/manifests/$baseName-$hash.nixmanifest";
+    my $finalPath = "$manifestDir/$baseName-$hash.nixmanifest";
     
-    system ("@coreutils@/mv", "-f", "$manifest", "$finalPath") == 0
-        or die "cannot move `$manifest' to `$finalPath";
+    system("@coreutils@/ln", "-sfn", "$manifest", "$finalPath") == 0
+        or die "cannot link `$finalPath to `$manifest'";
 }
 
 while (@ARGV) {
@@ -81,30 +103,5 @@ while (@ARGV) {
 }
 
 
-my $size = scalar (keys %narFiles);
+my $size = scalar (keys %narFiles) + scalar (keys %localPaths);
 print "$size store paths in manifest\n";
-
-
-# Register all substitutes.
-print STDERR "registering substitutes...\n";
-
-my $pid = open(WRITE, "|$binDir/nix-store --register-substitutes")
-    or die "cannot run nix-store";
-
-foreach my $storePath (keys %narFiles) {
-    my $narFileList = $narFiles{$storePath};
-    foreach my $narFile (@{$narFileList}) {
-        print WRITE "$storePath\n";
-        print WRITE "$narFile->{deriver}\n";
-        print WRITE "$libexecDir/nix/download-using-manifests.pl\n";
-        print WRITE "0\n";
-        my @references = split " ", $narFile->{references};
-        my $count = scalar @references;
-        print WRITE "$count\n";
-        foreach my $reference (@references) {
-            print WRITE "$reference\n";
-        }
-    }
-}
-
-close WRITE or die "nix-store failed: $?";

scripts/nix-push.in

@@ -16,8 +16,7 @@ my $curl = "@curl@ --fail --silent";
 my $extraCurlFlags = ${ENV{'CURL_FLAGS'}};
 $curl = "$curl $extraCurlFlags" if defined $extraCurlFlags;
 
-my $binDir = $ENV{"NIX_BIN_DIR"};
-$binDir = "@bindir@" unless defined $binDir;
+my $binDir = $ENV{"NIX_BIN_DIR"} || "@bindir@";
 
 my $dataDir = $ENV{"NIX_DATA_DIR"};
 $dataDir = "@datadir@" unless defined $dataDir;
@@ -107,7 +106,7 @@ foreach my $storePath (@storePaths) {
     # Construct a Nix expression that creates a Nix archive.
     my $nixexpr = 
         "((import $dataDir/nix/corepkgs/nar/nar.nix) " .
-        "{storePath = builtins.toPath \"$storePath\"; system = \"@system@\"; hashAlgo = \"$hashAlgo\";}) ";
+        "{storePath = builtins.storePath \"$storePath\"; system = \"@system@\"; hashAlgo = \"$hashAlgo\";}) ";
     
     print NIX $nixexpr;
 }
@@ -116,9 +115,9 @@ print NIX "]";
 close NIX;
 
 
-# Instantiate store expressions from the Nix expression.
+# Instantiate store derivations from the Nix expression.
 my @storeExprs;
-print STDERR "instantiating store expressions...\n";
+print STDERR "instantiating store derivations...\n";
 my $pid = open(READ, "$binDir/nix-instantiate $nixExpr|")
     or die "cannot run nix-instantiate";
 while (<READ>) {
@@ -129,7 +128,7 @@ while (<READ>) {
 close READ or die "nix-instantiate failed: $?";
 
 
-# Realise the store expressions.
+# Build the derivations.
 print STDERR "creating archives...\n";
 
 my @narPaths;
@@ -141,11 +140,6 @@ while (scalar @tmp > 0) {
     my @tmp2 = @tmp[0..$n - 1];
     @tmp = @tmp[$n..scalar @tmp - 1];
 
-    # Note: we disable build hooks because of the impure path
-    # reference (see above).  Even if that is fixed, using a hook
-    # probably wouldn't make that much sense; pumping lots of data
-    # around just to compress them won't gain that much.
-    $ENV{"NIX_BUILD_HOOK"} = "";
     my $pid = open(READ, "$binDir/nix-store --realise @tmp2|")
         or die "cannot run nix-store";
     while (<READ>) {
@@ -224,13 +218,14 @@ writeManifest $manifest, \%narFiles, \%patches;
 sub copyFile {
     my $src = shift;
     my $dst = shift;
-    system("@coreutils@/cp", $src, "$dst.tmp") == 0 or die "cannot copy file";
-    rename("$dst.tmp", "$dst") or die "cannot rename file";
+    my $tmp = "$dst.tmp.$$";
+    system("@coreutils@/cp", $src, $tmp) == 0 or die "cannot copy file";
+    rename($tmp, $dst) or die "cannot rename file: $!";
 }
 
 
-# Upload the archives.
-print STDERR "uploading archives...\n";
+# Upload/copy the archives.
+print STDERR "uploading/copying archives...\n";
 
 sub archiveExists {
     my $name = shift;
@@ -244,9 +239,12 @@ foreach my $narArchive (@narArchives) {
     my $basename = $1;
 
     if ($localCopy) {
+        # Since nix-push creates $dst atomically, if it exists we
+        # don't have to copy again.
+        my $dst = "$localArchivesDir/$basename";
         if (! -f "$localArchivesDir/$basename") {
             print STDERR "  $narArchive\n";
-            copyFile $narArchive, "$localArchivesDir/$basename";
+            copyFile $narArchive, $dst;
         }
     }
     else {
@@ -264,8 +262,12 @@ foreach my $narArchive (@narArchives) {
 print STDERR "uploading manifest...\n";
 if ($localCopy) {
     copyFile $manifest, $localManifestFile;
+    copyFile "$manifest.bz2", "$localManifestFile.bz2";
 } else {
-    system("$curl  --show-error --upload-file " .
+    system("$curl --show-error --upload-file " .
            "'$manifest' '$manifestPutURL' > /dev/null") == 0 or
            die "curl failed on $manifest: $?";
+    system("$curl --show-error --upload-file " .
+           "'$manifest'.bz2 '$manifestPutURL'.bz2 > /dev/null") == 0 or
+           die "curl failed on $manifest: $?";
 }

scripts/nix-reduce-build.in

@@ -0,0 +1,171 @@
+#! @shell@
+
+WORKING_DIRECTORY=$(mktemp -d "${TMPDIR:-/tmp}"/nix-reduce-build-XXXXXX);
+cd "$WORKING_DIRECTORY";
+
+if test -z "$1" || test "a--help" = "a$1" ; then
+	echo 'nix-reduce-build (paths or Nix expressions) -- (package sources)' >&2
+	echo As in: >&2
+	echo nix-reduce-build /etc/nixos/nixos -- ssh://user@somewhere.nowhere.example.org >&2
+	echo nix-reduce-build /etc/nixos/nixos -- \\
+	echo "   " \''http://somewhere.nowhere.example.org/nix/nix-http-export.cgi?needed_path='\' >&2
+	echo "  store path name will be added into the end of the URL" >&2
+	echo nix-reduce-build /etc/nixos/nixos -- file://home/user/nar/ >&2
+	echo "  that should be a directory where gzipped 'nix-store --export' ">&2
+	echo "  files are located (they should have .nar.gz extension)"  >&2
+	echo "        Or all together: " >&2
+	echo -e nix-reduce-build /expr.nix /e2.nix -- \\\\\\\n\
+	"    ssh://a@b.example.com http://n.example.com/get-nar?q= file://nar/" >&2
+	echo "        Also supports best-effort local builds of failing expression set:" >&2
+	echo "nix-reduce-build /e.nix -- nix-daemon:// nix-self://" >&2
+	echo "  nix-daemon:// builds using daemon"
+	echo "  nix-self:// builds directly using nix-store from current installation" >&2
+	echo "  nix-daemon-fixed:// and nix-self-fixed:// do the same, but only for" >&2;
+	echo "derivations with specified output hash (sha256, sha1 or md5)." >&2
+	echo "  nix-daemon-substitute:// and nix-self-substitute:// try to substitute" >&2;
+	echo "maximum amount of paths" >&2;
+	echo "  nix-daemon-build:// and nix-self-build:// try to build (not substitute)" >&2;
+	echo "maximum amount of paths" >&2;
+	echo "        If no package sources are specified, required paths are listed." >&2;
+	exit;
+fi;
+
+while ! test "$1" = "--" || test "$1" = "" ; do 
+	echo "$1" >> initial; >&2
+	shift;
+done
+shift;
+echo Will work on $(cat initial | wc -l) targets. >&2
+
+while read ; do
+	case "$REPLY" in 
+		${NIX_STORE_DIR:-/nix/store}/*)
+			echo "$REPLY" >> paths; >&2
+			;;
+		*)
+			(
+				IFS=: ;
+				nix-instantiate $REPLY >> paths;
+			);
+			;;
+	esac;
+done < initial;
+echo Proceeding $(cat paths | wc -l) paths. >&2
+
+while read; do
+	case "$REPLY" in
+		*.drv)
+			echo "$REPLY" >> derivers; >&2
+			;;
+		*)
+			nix-store --query --deriver "$REPLY" >>derivers;
+			;;
+	esac;
+done < paths;
+echo Found $(cat derivers | wc -l) derivers. >&2
+
+cat derivers | xargs nix-store --query -R > derivers-closure;
+echo Proceeding at most $(cat derivers-closure | wc -l) derivers. >&2
+
+cat derivers-closure | egrep '[.]drv$' | xargs nix-store --query --outputs > wanted-paths;
+cat derivers-closure | egrep -v '[.]drv$' >> wanted-paths;
+echo Prepared $(cat wanted-paths | wc -l) paths to get. >&2
+
+cat wanted-paths | xargs nix-store --check-validity --print-invalid > needed-paths;
+echo We need $(cat needed-paths | wc -l) paths. >&2
+
+egrep '[.]drv$' derivers-closure > critical-derivers;
+
+if test -z "$1" ; then
+	cat needed-paths;	
+fi;
+
+refresh_critical_derivers() {
+    echo "Finding needed derivers..." >&2;
+    cat critical-derivers | while read; do
+        if ! (nix-store --query --outputs "$REPLY" | xargs nix-store --check-validity &> /dev/null;); then
+            echo "$REPLY";
+        fi;
+    done > new-critical-derivers;
+    mv new-critical-derivers critical-derivers;
+    echo The needed paths are realized by $(cat critical-derivers | wc -l) derivers. >&2
+}
+
+build_here() {
+    cat critical-derivers | while read; do 
+        echo "Realising $REPLY using nix-daemon" >&2
+        @bindir@/nix-store -r "${REPLY}"
+    done;
+}
+
+try_to_substitute(){
+    cat needed-paths | while read ; do 
+        echo "Building $REPLY using nix-daemon" >&2
+        @bindir@/nix-store -r "${NIX_STORE_DIR:-/nix/store}/${REPLY##*/}"
+    done;
+}
+
+for i in "$@"; do 
+	sshHost="${i#ssh://}";
+	httpHost="${i#http://}";
+	httpsHost="${i#https://}";
+	filePath="${i#file:/}";
+	if [ "$i" != "$sshHost" ]; then
+		cat needed-paths | while read; do 
+			echo "Getting $REPLY and its closure over ssh" >&2
+			nix-copy-closure --from "$sshHost" --gzip "$REPLY" </dev/null || true; 
+		done;
+	elif [ "$i" != "$httpHost" ] || [ "$i" != "$httpsHost" ]; then
+		cat needed-paths | while read; do
+			echo "Getting $REPLY over http/https" >&2
+			curl ${BAD_CERTIFICATE:+-k} -L "$i${REPLY##*/}" | gunzip | nix-store --import;
+		done;
+	elif [ "$i" != "$filePath" ] ; then
+		cat needed-paths | while read; do 
+			echo "Installing $REPLY from file" >&2
+			gunzip < "$filePath/${REPLY##*/}".nar.gz | nix-store --import;
+		done;
+	elif [ "$i" = "nix-daemon://" ] ; then
+		NIX_REMOTE=daemon try_to_substitute;
+		refresh_critical_derivers;
+		NIX_REMOTE=daemon build_here;
+	elif [ "$i" = "nix-self://" ] ; then
+		NIX_REMOTE= try_to_substitute;
+		refresh_critical_derivers;
+		NIX_REMOTE= build_here;
+	elif [ "$i" = "nix-daemon-fixed://" ] ; then
+		refresh_critical_derivers;
+
+		cat critical-derivers | while read; do 
+			if egrep '"(md5|sha1|sha256)"' "$REPLY" &>/dev/null; then
+				echo "Realising $REPLY using nix-daemon" >&2
+				NIX_REMOTE=daemon @bindir@/nix-store -r "${REPLY}"
+			fi;
+		done;
+	elif [ "$i" = "nix-self-fixed://" ] ; then
+		refresh_critical_derivers;
+
+		cat critical-derivers | while read; do 
+			if egrep '"(md5|sha1|sha256)"' "$REPLY" &>/dev/null; then
+				echo "Realising $REPLY using direct Nix build" >&2
+				NIX_REMOTE= @bindir@/nix-store -r "${REPLY}"
+			fi;
+		done;
+	elif [ "$i" = "nix-daemon-substitute://" ] ; then
+		NIX_REMOTE=daemon try_to_substitute;
+	elif [ "$i" = "nix-self-substitute://" ] ; then
+		NIX_REMOTE= try_to_substitute;
+	elif [ "$i" = "nix-daemon-build://" ] ; then
+		refresh_critical_derivers;
+		NIX_REMOTE=daemon build_here;
+	elif [ "$i" = "nix-self-build://" ] ; then
+		refresh_critical_derivers;
+		NIX_REMOTE= build_here;
+	fi;
+	mv needed-paths wanted-paths;
+	cat wanted-paths | xargs nix-store --check-validity --print-invalid > needed-paths;
+	echo We still need $(cat needed-paths | wc -l) paths. >&2
+done;
+
+cd /
+rm -r "$WORKING_DIRECTORY"

scripts/nix-unpack-closure.in

@@ -1,79 +0,0 @@
-#! @perl@ -w
-
-# This tool unpacks the closures created by "nix-pack-closure" and
-# adds them to the Nix store.
-
-# TODO: make this program "streamy", i.e., don't use a temporary
-# directory.
-
-use strict;
-use File::Temp qw(tempdir);
-
-my $binDir = $ENV{"NIX_BIN_DIR"};
-$binDir = "@bindir@" unless defined $binDir;
-
-my $tmpDir = tempdir("nix-unpack-closure.XXXXXX", CLEANUP => 1, TMPDIR => 1)
-    or die "cannot create a temporary directory";
-
-
-# Unpack the NAR archive on standard input.
-system("nix-store --restore '$tmpDir/unpacked'") == 0
-    or die "nix-store --restore failed";
-
-
-open VALID, ">$tmpDir/validity" or die;
-
-
-# For each path in the closure that is not yet valid, add it to the
-# store.  TODO: use proper locking.  Or even better, let nix-store do
-# this.
-opendir(DIR, "$tmpDir/unpacked/contents") or die "cannot open directory: $!";
-
-foreach my $name (sort(readdir DIR)) {
-    next if $name eq "." or $name eq "..";
-
-    my $storePath = "@storedir@/$name"; # !!!
-
-    # !!! this really isn't a good validity check!
-    system "$binDir/nix-store --check-validity '$storePath' 2> /dev/null";
-    if ($? != 0) {
-        print STDERR "unpacking `$storePath'...\n";
-
-        # !!! race
-        system("@coreutils@/rm -rf '$storePath'") == 0
-            or die "cannot remove `$storePath': $?";
-
-        system("$binDir/nix-store --restore '$storePath' < '$tmpDir/unpacked/contents/$name'") == 0
-            or die "nix-store --dump failed on `$storePath': $?";
-        
-        print VALID "$storePath\n";
-
-        open DRV, "<$tmpDir/unpacked/derivers/$name" or die;
-        my $deriver = <DRV>;
-        chomp $deriver;
-        $deriver = "" if $deriver eq "unknown-deriver";
-        close DRV;
-
-        my @refs;
-        open REFS, "<$tmpDir/unpacked/references/$name" or die;
-        while (<REFS>) {
-            chomp;
-            push @refs, $_;
-        }
-        close REFS;
-
-        print VALID "$deriver\n";
-        
-        print VALID (scalar @refs), "\n";
-        foreach my $ref (@refs) {
-            print VALID "$ref\n";
-        }
-    }
-}
-
-closedir(DIR) or die;
-
-
-# Register the invalid paths as valid.
-system("nix-store --register-validity <'$tmpDir/validity'") == 0
-    or die "nix-store --register-validity failed";

scripts/optimise-store.pl

@@ -1,91 +0,0 @@
-#! /usr/bin/perl -w
-
-use strict;
-use File::Basename;
-
-
-my @paths = ("/nix/store");
-
-
-print "hashing...\n";
-
-my $hashList = "/tmp/nix-optimise-hash-list";
-
-system("find @paths -type f -print0 | xargs -0 md5sum -- > $hashList") == 0
-    or die "cannot hash store files";
-
-
-print "sorting by hash...\n";
-
-system("sort $hashList > $hashList.sorted") == 0
-    or die "cannot sort list";
-
-
-sub atomicLink {
-    my $target = shift;
-    my $new = shift;
-    my $tmpNew = "${new}_optimise.$$";
-
-    # Make the directory writable temporarily.
-    my $dir = dirname $new;
-    my @st = stat $dir or die;
-
-    chmod ($st[2] | 0200, $dir) or die "cannot make `$dir' writable: $!";
-    
-    link $target, $tmpNew or die "cannot create hard link `$tmpNew': $!";
-
-    rename $tmpNew, $new or die "cannot rename `$tmpNew' to `$new': $!";
-
-    chmod ($st[2], $dir) or die "cannot restore permission on `$dir': $!";
-    utime ($st[8], $st[9], $dir) or die "cannot restore timestamp on `$dir': $!";
-}
-
-
-print "hard-linking...\n";
-
-open LIST, "<$hashList.sorted" or die;
-
-my $prevFile;
-my $prevHash;
-my $prevInode;
-my $prevExec;
-
-my $totalSpace = 0;
-my $savedSpace = 0;
-
-while (<LIST>) {
-    /^([0-9a-f]*)\s+(.*)$/ or die;
-    my $curFile = $2;
-    my $curHash = $1;
-
-    my @st = stat $curFile or die;
-    next if ($st[2] & 0222) != 0; # skip writable files
-
-    my $fileSize = $st[7];
-    $totalSpace += $fileSize;
-    my $isExec = ($st[2] & 0111) == 0111;
-
-    if (defined $prevHash && $curHash eq $prevHash
-        && $prevExec == $isExec)
-    {
-        
-        if ($st[1] != $prevInode) {
-            print "$curFile = $prevFile\n";
-            atomicLink $prevFile, $curFile;
-            $savedSpace += $fileSize;
-        }
-        
-    } else {
-        $prevFile = $curFile;
-        $prevHash = $curHash;
-        $prevInode = $st[1];
-        $prevExec = ($st[2] & 0111) == 0111;
-    }
-}
-
-print "total space = $totalSpace\n";
-print "saved space = $savedSpace\n";
-my $savings = ($savedSpace / $totalSpace) * 100.0;
-print "savings = $savings %\n";
-
-close LIST;

scripts/readmanifest.pm.in

@@ -2,10 +2,7 @@ use strict;
 
 
 sub addPatch {
-    my $patches = shift;
-    my $storePath = shift;
-    my $patch = shift;
-    my $allowConflicts = shift;
+    my ($patches, $storePath, $patch) = @_;
 
     $$patches{$storePath} = []
         unless defined $$patches{$storePath};
@@ -14,15 +11,9 @@ sub addPatch {
 
     my $found = 0;
     foreach my $patch2 (@{$patchList}) {
-        if ($patch2->{url} eq $patch->{url}) {
-            if ($patch2->{hash} eq $patch->{hash}) {
-                $found = 1 if ($patch2->{basePath} eq $patch->{basePath});
-            } else {
-                die "conflicting hashes for URL $patch->{url}, " .
-                    "namely $patch2->{hash} and $patch->{hash}"
-                    unless $allowConflicts;
-            }
-        }
+        $found = 1 if
+            $patch2->{url} eq $patch->{url} &&
+            $patch2->{basePath} eq $patch->{basePath};
     }
     
     push @{$patchList}, $patch if !$found;
@@ -32,12 +23,7 @@ sub addPatch {
 
 
 sub readManifest {
-    my $manifest = shift;
-    my $narFiles = shift;
-    my $patches = shift;
-    my $successors = shift;
-    my $allowConflicts = shift;
-    $allowConflicts = 0 unless defined $allowConflicts;
+    my ($manifest, $narFiles, $localPaths, $patches) = @_;
 
     open MANIFEST, "<$manifest"
         or die "cannot open `$manifest': $!";
@@ -51,7 +37,6 @@ sub readManifest {
     my $url;
     my $hash;
     my $size;
-    my @preds;
     my $basePath;
     my $baseHash;
     my $patchType;
@@ -59,6 +44,7 @@ sub readManifest {
     my $references;
     my $deriver;
     my $hashAlgo;
+    my $copyFrom;
 
     while (<MANIFEST>) {
         chomp;
@@ -75,7 +61,6 @@ sub readManifest {
                 undef $url;
                 undef $hash;
                 undef $size;
-                @preds = ();
                 undef $narHash;
                 undef $basePath;
                 undef $baseHash;
@@ -99,15 +84,7 @@ sub readManifest {
 
                     my $found = 0;
                     foreach my $narFile (@{$narFileList}) {
-                        if ($narFile->{url} eq $url) {
-                            if ($narFile->{hash} eq $hash) {
-                                $found = 1;
-                            } else {
-                                die "conflicting hashes for URL $url, " .
-                                    "namely $narFile->{hash} and $hash"
-                                    unless $allowConflicts;
-                            }
-                        }
+                        $found = 1 if $narFile->{url} eq $url;
                     }
                     if (!$found) {
                         push @{$narFileList},
@@ -117,10 +94,6 @@ sub readManifest {
                             };
                     }
                 
-                    foreach my $p (@preds) {
-                        $$successors{$p} = $storePath;
-                    }
-
                 }
 
                 elsif ($type eq "patch") {
@@ -129,16 +102,32 @@ sub readManifest {
                         , basePath => $basePath, baseHash => $baseHash
                         , narHash => $narHash, patchType => $patchType
                         , hashAlgo => $hashAlgo
-                        }, $allowConflicts;
+                        };
+                }
+
+                elsif ($type eq "localPath") {
+
+                    $$localPaths{$storePath} = []
+                        unless defined $$localPaths{$storePath};
+
+                    my $localPathsList = $$localPaths{$storePath};
+
+                    # !!! remove duplicates
+                    
+                    push @{$localPathsList},
+                        { copyFrom => $copyFrom, references => $references
+                        , deriver => ""
+                        };
                 }
 
             }
             
             elsif (/^\s*StorePath:\s*(\/\S+)\s*$/) { $storePath = $1; }
+            elsif (/^\s*CopyFrom:\s*(\/\S+)\s*$/) { $copyFrom = $1; }
             elsif (/^\s*Hash:\s*(\S+)\s*$/) { $hash = $1; }
             elsif (/^\s*URL:\s*(\S+)\s*$/) { $url = $1; }
             elsif (/^\s*Size:\s*(\d+)\s*$/) { $size = $1; }
-            elsif (/^\s*SuccOf:\s*(\/\S+)\s*$/) { push @preds, $1; }
+            elsif (/^\s*SuccOf:\s*(\/\S+)\s*$/) { } # obsolete
             elsif (/^\s*BasePath:\s*(\/\S+)\s*$/) { $basePath = $1; }
             elsif (/^\s*BaseHash:\s*(\S+)\s*$/) { $baseHash = $1; }
             elsif (/^\s*Type:\s*(\S+)\s*$/) { $patchType = $1; }
@@ -160,11 +149,8 @@ sub readManifest {
 }
 
 
-sub writeManifest
-{
-    my $manifest = shift;
-    my $narFiles = shift;
-    my $patches = shift;
+sub writeManifest {
+    my ($manifest, $narFiles, $patches) = @_;
 
     open MANIFEST, ">$manifest.tmp"; # !!! check exclusive
 
@@ -178,9 +164,9 @@ sub writeManifest
             print MANIFEST "{\n";
             print MANIFEST "  StorePath: $storePath\n";
             print MANIFEST "  NarURL: $narFile->{url}\n";
-            print MANIFEST "  Hash: $narFile->{hash}\n";
+            print MANIFEST "  Hash: $narFile->{hash}\n" if defined $narFile->{hash};
             print MANIFEST "  NarHash: $narFile->{narHash}\n";
-            print MANIFEST "  Size: $narFile->{size}\n";
+            print MANIFEST "  Size: $narFile->{size}\n" if defined $narFile->{size};
             print MANIFEST "  References: $narFile->{references}\n"
                 if defined $narFile->{references} && $narFile->{references} ne "";
             print MANIFEST "  Deriver: $narFile->{deriver}\n"
@@ -210,6 +196,14 @@ sub writeManifest
 
     rename("$manifest.tmp", $manifest)
         or die "cannot rename $manifest.tmp: $!";
+
+
+    # Create a bzipped manifest.
+    system("@bzip2@ < $manifest > $manifest.bz2.tmp") == 0
+        or die "cannot compress manifest";
+
+    rename("$manifest.bz2.tmp", "$manifest.bz2")
+        or die "cannot rename $manifest.bz2.tmp: $!";
 }
 
 

scripts/remove-patches.pl

@@ -6,14 +6,12 @@ use readmanifest;
 for my $p (@ARGV) {
 
     my %narFiles;
+    my %localPaths;
     my %patches;
-    my %successors;
 
-    readManifest $p,
-        \%narFiles, \%patches, \%successors;
+    readManifest $p, \%narFiles, \%localPaths, \%patches;
 
     %patches = ();
     
-    writeManifest $p,
-        \%narFiles, \%patches, \%successors;
+    writeManifest $p, \%narFiles, \%patches;
 }

scripts/update-manifest.pl

@@ -8,10 +8,10 @@ die unless scalar @ARGV == 2;
 my $cache = $ARGV[0];
 my $manifest = $ARGV[1];
 my %narFiles;
+my %localPaths;
 my %patches;
-my %successors;
 
-readManifest $manifest, \%narFiles, \%patches, \%successors;
+readManifest $manifest, \%narFiles, \%localPaths, \%patches;
 
 foreach my $storePath (keys %narFiles) {
     my $narFileList = $narFiles{$storePath};
@@ -50,4 +50,4 @@ if (! -e "$manifest.backup") {
     system "mv --reply=no '$manifest' '$manifest.backup'";
 }
 
-writeManifest $manifest, \%narFiles, \%patches, \%successors;
+writeManifest $manifest, \%narFiles, \%patches;

src/Makefile.am

@@ -1,15 +1,5 @@
 SUBDIRS = bin2c boost libutil libstore libmain nix-store nix-hash \
- libexpr nix-instantiate nix-env nix-log2xml bsdiff-4.3
+ libexpr nix-instantiate nix-env nix-worker nix-setuid-helper \
+ nix-log2xml bsdiff-4.3
 
 EXTRA_DIST = aterm-helper.pl
-
-SETUID_PROGS = nix-store nix-instantiate nix-env
-install-exec-hook:
-if SETUID_HACK
-if HAVE_SETRESUID
-	cd $(DESTDIR)$(bindir) && chown @NIX_USER@ $(SETUID_PROGS) \
-	  && chgrp @NIX_GROUP@ $(SETUID_PROGS) && chmod ug+s $(SETUID_PROGS)
-else
-	cd $(DESTDIR)$(bindir) && chown root $(SETUID_PROGS) && chmod u+s $(SETUID_PROGS)
-endif
-endif

src/aterm-helper.pl

@@ -47,6 +47,7 @@ print HEADER "#endif\n\n\n";
 print IMPL "namespace nix {\n";
 
 while (<STDIN>) {
+    s/\#.*//;
     next if (/^\s*$/);
     
     if (/^\s*(\w*)\s*\|([^\|]*)\|\s*(\w+)\s*\|\s*(\w+)?/) {

src/boost/Makefile.am

@@ -1,6 +1,6 @@
 SUBDIRS = format
 
-pkginclude_HEADERS = assert.hpp checked_delete.hpp format.hpp \
+nobase_pkginclude_HEADERS = assert.hpp checked_delete.hpp format.hpp \
  shared_ptr.hpp weak_ptr.hpp throw_exception.hpp \
  enable_shared_from_this.hpp \
  detail/shared_count.hpp detail/workaround.hpp

src/bsdiff-4.3/bspatch.c

@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD: src/usr.bin/bsdiff/bspatch/bspatch.c,v 1.1 2005/08/06 01:59:
 #include <errno.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <sys/types.h>
 
 static off_t offtin(u_char *buf)
 {

src/libexpr/Makefile.am

@@ -2,11 +2,13 @@ pkglib_LTLIBRARIES = libexpr.la
 
 libexpr_la_SOURCES = \
  nixexpr.cc eval.cc primops.cc lexer-tab.cc parser-tab.cc \
- get-drvs.cc attr-path.cc expr-to-xml.cc
+ get-drvs.cc attr-path.cc expr-to-xml.cc common-opts.cc \
+ names.cc normal-forms.cc
 
 pkginclude_HEADERS = \
  nixexpr.hh eval.hh parser.hh lexer-tab.hh parser-tab.hh \
- get-drvs.hh attr-path.hh expr-to-xml.hh
+ get-drvs.hh attr-path.hh expr-to-xml.hh common-opts.hh \
+ names.hh nixexpr-ast.hh
 
 libexpr_la_LIBADD = ../libutil/libutil.la ../libstore/libstore.la \
  ../boost/format/libformat.la

src/libexpr/attr-path.cc

@@ -46,7 +46,7 @@ Expr findAlongAttrPath(EvalState & state, const string & attrPath,
 
         if (apType == apAttr) {
 
-            ATermMap attrs(128);
+            ATermMap attrs;
 
             if (!isAttrs(state, e, attrs))
                 throw TypeError(

src/libexpr/common-opts.cc

@@ -0,0 +1,32 @@
+#include "common-opts.hh"
+#include "../libmain/shared.hh"
+#include "util.hh"
+#include "parser.hh"
+
+
+namespace nix {
+
+
+bool parseOptionArg(const string & arg, Strings::iterator & i,
+    const Strings::iterator & argsEnd, EvalState & state,
+    ATermMap & autoArgs)
+{
+    if (arg != "--arg" && arg != "--argstr") return false;
+
+    UsageError error(format("`%1%' requires two arguments") % arg);
+    
+    if (i == argsEnd) throw error;
+    string name = *i++;
+    if (i == argsEnd) throw error;
+    string value = *i++;
+    
+    Expr e = arg == "--arg"
+        ? parseExprFromString(state, value, absPath("."))
+        : makeStr(value);
+    autoArgs.set(toATerm(name), e);
+    
+    return true;
+}
+
+ 
+}

src/libexpr/common-opts.hh

@@ -0,0 +1,17 @@
+#ifndef __COMMON_OPTS_H
+#define __COMMON_OPTS_H
+
+#include "eval.hh"
+
+
+namespace nix {
+
+/* Some common option parsing between nix-env and nix-instantiate. */
+bool parseOptionArg(const string & arg, Strings::iterator & i,
+    const Strings::iterator & argsEnd, EvalState & state,
+    ATermMap & autoArgs);
+    
+}
+
+
+#endif /* !__COMMON_OPTS_H */

src/libexpr/eval.hh

@@ -30,6 +30,7 @@ typedef Expr (* PrimOp) (EvalState &, const ATermVector & args);
 struct EvalState 
 {
     ATermMap normalForms;
+    ATermMap sessionNormalForms;
     ATermMap primOps;
     DrvRoots drvRoots;
     DrvHashes drvHashes; /* normalised derivation hashes */
@@ -37,12 +38,19 @@ struct EvalState
 
     unsigned int nrEvaluated;
     unsigned int nrCached;
+    unsigned int nrDepthAfterReset;
+
+    bool allowUnsafeEquality;
+    bool safeCache;
 
     EvalState();
+    ~EvalState();
 
     void addPrimOps();
     void addPrimOp(const string & name,
         unsigned int arity, PrimOp primOp);
+    void loadNormalForms();
+    void saveNormalForms();
 };
 
 
@@ -56,21 +64,29 @@ Expr evalFile(EvalState & state, const Path & path);
    attributes.  If `canonicalise' is true, we remove things like
    position information and make sure that attribute sets are in
    sorded order. */
-Expr strictEvalExpr(EvalState & state, Expr e,
-    bool canonicalise = false);
+Expr strictEvalExpr(EvalState & state, Expr e);
 
 /* Specific results. */
-string evalString(EvalState & state, Expr e);
-Path evalPath(EvalState & state, Expr e);
+string evalString(EvalState & state, Expr e, PathSet & context);
+string evalStringNoCtx(EvalState & state, Expr e);
 int evalInt(EvalState & state, Expr e);
 bool evalBool(EvalState & state, Expr e);
 ATermList evalList(EvalState & state, Expr e);
-ATerm coerceToString(Expr e);
 
-/* Contexts. */
-string coerceToStringWithContext(EvalState & state,
-    ATermList & context, Expr e, bool & isPath);
-Expr wrapInContext(ATermList context, Expr e);
+/* Flatten nested lists into a single list (or expand a singleton into
+   a list). */
+ATermList flattenList(EvalState & state, Expr e);
+
+/* String coercion.  Converts strings, paths and derivations to a
+   string.  If `coerceMore' is set, also converts nulls, integers,
+   booleans and lists to a string. */
+string coerceToString(EvalState & state, Expr e, PathSet & context,
+    bool coerceMore = false, bool copyToStore = true);
+
+/* Path coercion.  Converts strings, paths and derivations to a path.
+   The result is guaranteed to be an canonicalised, absolute path.
+   Nothing is copied to the store. */
+Path coerceToPath(EvalState & state, Expr e, PathSet & context);
 
 /* Automatically call a function for which each argument has a default
    value or has a binding in the `args' map.  Note: result is a call,

src/libexpr/expr-to-xml.cc

@@ -2,6 +2,9 @@
 #include "xml-writer.hh"
 #include "nixexpr-ast.hh"
 #include "aterm.hh"
+#include "util.hh"
+
+#include <cstdlib>
 
 
 namespace nix {
@@ -15,29 +18,70 @@ static XMLAttrs singletonAttrs(const string & name, const string & value)
 }
 
 
-static void printTermAsXML(Expr e, XMLWriter & doc, ATermList & context)
+/* set<Expr> is safe because all the expressions are also reachable
+   from the stack, therefore can't be garbage-collected. */
+typedef set<Expr> ExprSet;
+
+
+static void printTermAsXML(Expr e, XMLWriter & doc, PathSet & context,
+    ExprSet & drvsSeen);
+
+
+static void showAttrs(const ATermMap & attrs, XMLWriter & doc,
+    PathSet & context, ExprSet & drvsSeen)
+{
+    StringSet names;
+    for (ATermMap::const_iterator i = attrs.begin(); i != attrs.end(); ++i)
+        names.insert(aterm2String(i->key));
+    for (StringSet::iterator i = names.begin(); i != names.end(); ++i) {
+        XMLOpenElement _(doc, "attr", singletonAttrs("name", *i));
+        printTermAsXML(attrs.get(toATerm(*i)), doc, context, drvsSeen);
+    }
+}
+
+
+static void printPatternAsXML(Pattern pat, XMLWriter & doc)
+{
+    ATerm name;
+    ATermList formals;
+    Pattern pat1, pat2;
+    ATermBool ellipsis;
+    if (matchVarPat(pat, name))
+        doc.writeEmptyElement("varpat", singletonAttrs("name", aterm2String(name)));
+    else if (matchAttrsPat(pat, formals, ellipsis)) {
+        XMLOpenElement _(doc, "attrspat");
+        for (ATermIterator i(formals); i; ++i) {
+            Expr name; ATerm dummy;
+            if (!matchFormal(*i, name, dummy)) abort();
+            doc.writeEmptyElement("attr", singletonAttrs("name", aterm2String(name)));
+        }
+        if (ellipsis == eTrue) doc.writeEmptyElement("ellipsis");
+    }
+    else if (matchAtPat(pat, pat1, pat2)) {
+        XMLOpenElement _(doc, "at");
+        printPatternAsXML(pat1, doc);
+        printPatternAsXML(pat2, doc);
+    }
+}
+
+
+static void printTermAsXML(Expr e, XMLWriter & doc, PathSet & context,
+    ExprSet & drvsSeen)
 {
     XMLAttrs attrs;
-    ATerm s;
+    string s;
+    ATerm s2;
     int i;
-    Expr e2;
-    ATermList as, es, formals;
-    ATerm body, pos;
+    ATermList as, es;
+    ATerm pat, body, pos;
 
-    while (matchContext(e, es, e2)) {
-        e = e2;
-        for (ATermIterator i(es); i; ++i)
-            context = ATinsert(context, *i);
-    }
+    checkInterrupt();
 
-    if (matchStr(e, s))
-        doc.writeEmptyElement("string", singletonAttrs("value", aterm2String(s)));
+    if (matchStr(e, s, context)) /* !!! show the context? */
+        doc.writeEmptyElement("string", singletonAttrs("value", s));
 
-    else if (matchPath(e, s))
-        doc.writeEmptyElement("path", singletonAttrs("value", aterm2String(s)));
-
-    else if (matchUri(e, s))
-        doc.writeEmptyElement("uri", singletonAttrs("value", aterm2String(s)));
+    else if (matchPath(e, s2))
+        doc.writeEmptyElement("path", singletonAttrs("value", aterm2String(s2)));
 
     else if (matchNull(e))
         doc.writeEmptyElement("null");
@@ -52,40 +96,47 @@ static void printTermAsXML(Expr e, XMLWriter & doc, ATermList & context)
         doc.writeEmptyElement("bool", singletonAttrs("value", "false"));
 
     else if (matchAttrs(e, as)) {
-        XMLOpenElement _(doc, "attrs");
-        ATermMap attrs(128);
+        ATermMap attrs;
         queryAllAttrs(e, attrs);
-        StringSet names;
-        for (ATermMap::const_iterator i = attrs.begin(); i != attrs.end(); ++i)
-            names.insert(aterm2String(i->key));
-        for (StringSet::iterator i = names.begin(); i != names.end(); ++i) {
-            XMLOpenElement _(doc, "attr", singletonAttrs("name", *i));
-            printTermAsXML(attrs.get(toATerm(*i)), doc, context);
+
+        Expr a = attrs.get(toATerm("type"));
+        if (a && matchStr(a, s, context) && s == "derivation") {
+
+            XMLAttrs xmlAttrs;
+            Path outPath, drvPath;
+            
+            a = attrs.get(toATerm("drvPath"));
+            if (matchStr(a, drvPath, context))
+                xmlAttrs["drvPath"] = drvPath;
+        
+            a = attrs.get(toATerm("outPath"));
+            if (matchStr(a, outPath, context))
+                xmlAttrs["outPath"] = outPath;
+        
+            XMLOpenElement _(doc, "derivation", xmlAttrs);
+
+            if (drvsSeen.find(e) == drvsSeen.end()) {
+                drvsSeen.insert(e);
+                showAttrs(attrs, doc, context, drvsSeen);
+            } else
+                doc.writeEmptyElement("repeated");
+        }
+
+        else {
+            XMLOpenElement _(doc, "attrs");
+            showAttrs(attrs, doc, context, drvsSeen);
         }
     }
 
     else if (matchList(e, es)) {
         XMLOpenElement _(doc, "list");
         for (ATermIterator i(es); i; ++i)
-            printTermAsXML(*i, doc, context);
+            printTermAsXML(*i, doc, context, drvsSeen);
     }
 
-    else if (matchFunction(e, formals, body, pos)) {
+    else if (matchFunction(e, pat, body, pos)) {
         XMLOpenElement _(doc, "function");
-        
-        for (ATermIterator i(formals); i; ++i) {
-            Expr name; ValidValues valids; ATerm dummy;
-            if (!matchFormal(*i, name, valids, dummy)) abort();
-            XMLOpenElement _(doc, "arg", singletonAttrs("name", aterm2String(name)));
-
-            ATermList valids2;
-            if (matchValidValues(valids, valids2)) {
-                for (ATermIterator j(valids2); j; ++j) {
-                    XMLOpenElement _(doc, "value");
-                    printTermAsXML(*j, doc, context);
-                }
-            }
-        }
+        printPatternAsXML(pat, doc);
     }
 
     else
@@ -93,11 +144,12 @@ static void printTermAsXML(Expr e, XMLWriter & doc, ATermList & context)
 }
 
 
-void printTermAsXML(Expr e, std::ostream & out, ATermList & context)
+void printTermAsXML(Expr e, std::ostream & out, PathSet & context)
 {
     XMLWriter doc(true, out);
     XMLOpenElement root(doc, "expr");
-    printTermAsXML(e, doc, context);
+    ExprSet drvsSeen;    
+    printTermAsXML(e, doc, context, drvsSeen);
 }
 
  

src/libexpr/expr-to-xml.hh

@@ -9,7 +9,7 @@
 
 namespace nix {
 
-void printTermAsXML(Expr e, std::ostream & out, ATermList & context);
+void printTermAsXML(Expr e, std::ostream & out, PathSet & context);
     
 }
 

src/libexpr/get-drvs.cc

@@ -10,7 +10,15 @@ string DrvInfo::queryDrvPath(EvalState & state) const
 {
     if (drvPath == "") {
         Expr a = attrs->get(toATerm("drvPath"));
-        (string &) drvPath = a ? evalPath(state, a) : "";
+
+        /* Backwards compatibility hack with user environments made by
+           Nix <= 0.10: these contain illegal Path("") expressions. */
+        ATerm t;
+        if (a && matchPath(evalExpr(state, a), t))
+            return aterm2String(t);
+        
+        PathSet context;
+        (string &) drvPath = a ? coerceToPath(state, a, context) : "";
     }
     return drvPath;
 }
@@ -21,7 +29,8 @@ string DrvInfo::queryOutPath(EvalState & state) const
     if (outPath == "") {
         Expr a = attrs->get(toATerm("outPath"));
         if (!a) throw TypeError("output path missing");
-        (string &) outPath = evalPath(state, a);
+        PathSet context;
+        (string &) outPath = coerceToPath(state, a, context);
     }
     return outPath;
 }
@@ -34,21 +43,66 @@ MetaInfo DrvInfo::queryMetaInfo(EvalState & state) const
     Expr a = attrs->get(toATerm("meta"));
     if (!a) return meta; /* fine, empty meta information */
 
-    ATermMap attrs2(16); /* !!! */
+    ATermMap attrs2;
     queryAllAttrs(evalExpr(state, a), attrs2);
 
     for (ATermMap::const_iterator i = attrs2.begin(); i != attrs2.end(); ++i) {
-        ATerm s = coerceToString(evalExpr(state, i->value));
-        if (s)
-            meta[aterm2String(i->key)] = aterm2String(s);
-        /* For future compatibility, ignore attribute values that are
-           not strings. */
+        Expr e = evalExpr(state, i->value);
+        string s;
+        PathSet context;
+        MetaValue value;
+        int n;
+        ATermList es;
+        if (matchStr(e, s, context)) {
+            value.type = MetaValue::tpString;
+            value.stringValue = s;
+            meta[aterm2String(i->key)] = value;
+        } else if (matchInt(e, n)) {
+            value.type = MetaValue::tpInt;
+            value.intValue = n;
+            meta[aterm2String(i->key)] = value;
+        } else if (matchList(e, es)) {
+            value.type = MetaValue::tpStrings;
+            for (ATermIterator j(es); j; ++j)
+                value.stringValues.push_back(evalStringNoCtx(state, *j));
+            meta[aterm2String(i->key)] = value;
+        }
     }
 
     return meta;
 }
 
 
+MetaValue DrvInfo::queryMetaInfo(EvalState & state, const string & name) const
+{
+    /* !!! evaluates all meta attributes => inefficient */
+    return queryMetaInfo(state)[name];
+}
+
+
+void DrvInfo::setMetaInfo(const MetaInfo & meta)
+{
+    ATermMap metaAttrs;
+    foreach (MetaInfo::const_iterator, i, meta) {
+        Expr e;
+        switch (i->second.type) {
+            case MetaValue::tpInt: e = makeInt(i->second.intValue); break;
+            case MetaValue::tpString: e = makeStr(i->second.stringValue); break;
+            case MetaValue::tpStrings: {
+                ATermList es = ATempty;
+                foreach (Strings::const_iterator, j, i->second.stringValues)
+                    es = ATinsert(es, makeStr(*j));
+                e = makeList(ATreverse(es));
+                break;
+            }
+            default: abort();
+        }
+        metaAttrs.set(toATerm(i->first), makeAttrRHS(e, makeNoPos()));
+    }
+    attrs->set(toATerm("meta"), makeAttrs(metaAttrs));
+}
+
+
 /* Cache for already evaluated derivations.  Usually putting ATerms in
    a STL container is unsafe (they're not scanning for GC roots), but
    here it doesn't matter; everything in this set is reachable from
@@ -70,11 +124,11 @@ static bool getDerivation(EvalState & state, Expr e,
         e = evalExpr(state, e);
         if (!matchAttrs(e, es)) return true;
 
-        boost::shared_ptr<ATermMap> attrs(new ATermMap(32)); /* !!! */
+        boost::shared_ptr<ATermMap> attrs(new ATermMap());
         queryAllAttrs(e, *attrs, false);
-    
+        
         Expr a = attrs->get(toATerm("type"));
-        if (!a || evalString(state, a) != "derivation") return true;
+        if (!a || evalStringNoCtx(state, a) != "derivation") return true;
 
         /* Remove spurious duplicates (e.g., an attribute set like
            `rec { x = derivation {...}; y = x;}'. */
@@ -86,13 +140,13 @@ static bool getDerivation(EvalState & state, Expr e,
         a = attrs->get(toATerm("name"));
         /* !!! We really would like to have a decent back trace here. */
         if (!a) throw TypeError("derivation name missing");
-        drv.name = evalString(state, a);
+        drv.name = evalStringNoCtx(state, a);
 
         a = attrs->get(toATerm("system"));
         if (!a)
             drv.system = "unknown";
         else
-            drv.system = evalString(state, a);
+            drv.system = evalStringNoCtx(state, a);
 
         drv.attrs = attrs;
 
@@ -140,23 +194,38 @@ static void getDerivations(EvalState & state, Expr e,
     if (matchAttrs(e, es)) {
         ATermMap drvMap(ATgetLength(es));
         queryAllAttrs(e, drvMap);
-        
-        for (ATermMap::const_iterator i = drvMap.begin(); i != drvMap.end(); ++i) {
-            startNest(nest, lvlDebug,
-                format("evaluating attribute `%1%'") % aterm2String(i->key));
-            string pathPrefix2 = addToPath(pathPrefix, aterm2String(i->key));
-            if (getDerivation(state, i->value, pathPrefix2, drvs, doneExprs)) {
+
+        /* !!! undocumented hackery to support combining channels in
+           nix-env.cc. */
+        bool combineChannels = drvMap.get(toATerm("_combineChannels"));
+
+        /* Consider the attributes in sorted order to get more
+           deterministic behaviour in nix-env operations (e.g. when
+           there are names clashes between derivations, the derivation
+           bound to the attribute with the "lower" name should take
+           precedence). */
+        typedef std::map<string, Expr> AttrsSorted;
+        AttrsSorted attrsSorted;
+        foreach (ATermMap::const_iterator, i, drvMap)
+            attrsSorted[aterm2String(i->key)] = i->value;
+
+        foreach (AttrsSorted::iterator, i, attrsSorted) {
+            startNest(nest, lvlDebug, format("evaluating attribute `%1%'") % i->first);
+            string pathPrefix2 = addToPath(pathPrefix, i->first);
+            if (combineChannels)
+                getDerivations(state, i->second, pathPrefix2, autoArgs, drvs, doneExprs);
+            else if (getDerivation(state, i->second, pathPrefix2, drvs, doneExprs)) {
                 /* If the value of this attribute is itself an
                    attribute set, should we recurse into it?  => Only
                    if it has a `recurseForDerivations = true'
                    attribute. */
                 ATermList es;
-                Expr e = evalExpr(state, i->value);
+                Expr e = evalExpr(state, i->second), e2;
                 if (matchAttrs(e, es)) {
                     ATermMap attrs(ATgetLength(es));
                     queryAllAttrs(e, attrs, false);
-                    Expr e2 = attrs.get(toATerm("recurseForDerivations"));
-                    if (e2 && evalBool(state, e2))
+                    if (((e2 = attrs.get(toATerm("recurseForDerivations")))
+                            && evalBool(state, e2)))
                         getDerivations(state, e, pathPrefix2, autoArgs, drvs, doneExprs);
                 }
             }

src/libexpr/get-drvs.hh

@@ -12,7 +12,16 @@
 namespace nix {
 
 
-typedef std::map<string, string> MetaInfo;
+struct MetaValue
+{
+    enum { tpNone, tpString, tpStrings, tpInt } type;
+    string stringValue;
+    Strings stringValues;
+    int intValue;
+};
+
+
+typedef std::map<string, MetaValue> MetaInfo;
 
 
 struct DrvInfo
@@ -26,11 +35,15 @@ public:
     string attrPath; /* path towards the derivation */
     string system;
 
+    /* !!! these should really be hidden, and setMetaInfo() should
+       make a copy since the ATermMap can be shared between multiple
+       DrvInfos. */
     boost::shared_ptr<ATermMap> attrs;
 
     string queryDrvPath(EvalState & state) const;
     string queryOutPath(EvalState & state) const;
     MetaInfo queryMetaInfo(EvalState & state) const;
+    MetaValue queryMetaInfo(EvalState & state, const string & name) const;
 
     void setDrvPath(const string & s)
     {
@@ -41,6 +54,8 @@ public:
     {
         outPath = s;
     }
+
+    void setMetaInfo(const MetaInfo & meta);
 };
 
 

src/libexpr/lexer.l

@@ -4,6 +4,7 @@
 
 
 %x STRING
+%x IND_STRING
 
 
 %{
@@ -64,7 +65,7 @@ static Expr unescapeStr(const char * s)
         }
         else t += c;
     }
-    return makeStr(toATerm(t));
+    return makeStr(toATerm(t), ATempty);
 }
 
  
@@ -94,6 +95,7 @@ let         { return LET; }
 in          { return IN; }
 rec         { return REC; }
 inherit     { return INHERIT; }
+\.\.\.      { return ELLIPSIS; }
 
 \=\=        { return EQ; }
 \!\=        { return NEQ; }
@@ -122,6 +124,30 @@ inherit     { return INHERIT; }
 <STRING>\"  { BEGIN(INITIAL); return '"'; }
 <STRING>.   return yytext[0]; /* just in case: shouldn't be reached */
 
+\'\'(\ *\n)?     { BEGIN(IND_STRING); return IND_STRING_OPEN; }
+<IND_STRING>([^\$\']|\$[^\{\']|\'[^\'\$])+ {
+                   yylval->t = makeIndStr(toATerm(yytext));
+                   return IND_STR;
+                 }
+<IND_STRING>\'\'\$ {
+                   yylval->t = makeIndStr(toATerm("$"));
+                   return IND_STR;
+                 }
+<IND_STRING>\'\'\' {
+                   yylval->t = makeIndStr(toATerm("''"));
+                   return IND_STR;
+                 }
+<IND_STRING>\'\'\\. {
+                   yylval->t = unescapeStr(yytext + 2);
+                   return IND_STR;
+                 }
+<IND_STRING>\$\{ { BEGIN(INITIAL); return DOLLAR_CURLY; }
+<IND_STRING>\'\' { BEGIN(INITIAL); return IND_STRING_CLOSE; }
+<IND_STRING>\'   {
+                   yylval->t = makeIndStr(toATerm("'"));
+                   return IND_STR;
+                 }
+<IND_STRING>.    return yytext[0]; /* just in case: shouldn't be reached */
 
 {PATH}      { yylval->t = toATerm(yytext); return PATH; /* !!! alloc */ }
 {URI}       { yylval->t = toATerm(yytext); return URI; /* !!! alloc */ }
@@ -148,4 +174,10 @@ void backToString(yyscan_t scanner)
     BEGIN(STRING);
 }
 
+void backToIndString(yyscan_t scanner)
+{
+    struct yyguts_t * yyg = (struct yyguts_t *) scanner;
+    BEGIN(IND_STRING);
+}
+
 }

src/libexpr/names.cc

@@ -92,25 +92,6 @@ int compareVersions(const string & v1, const string & v2)
 }
 
 
-static void testCompareVersions()
-{
-#define TEST(v1, v2, n) assert( \
-    compareVersions(v1, v2) == n && compareVersions(v2, v1) == -n)
-    TEST("1.0", "2.3", -1);
-    TEST("2.1", "2.3", -1);
-    TEST("2.3", "2.3", 0);
-    TEST("2.5", "2.3", 1);
-    TEST("3.1", "2.3", 1);
-    TEST("2.3.1", "2.3", 1);
-    TEST("2.3.1", "2.3a", 1);
-    TEST("2.3pre1", "2.3", -1);
-    TEST("2.3pre3", "2.3pre12", -1);
-    TEST("2.3a", "2.3c", -1);
-    TEST("2.3pre1", "2.3c", -1);
-    TEST("2.3pre1", "2.3q", -1);
-}
-
-
 DrvNames drvNamesFromArgs(const Strings & opArgs)
 {
     DrvNames result;

src/libexpr/nix.sdf

@@ -1,10 +1,13 @@
+%% Note: this SDF grammar is no longer used in the Nix expression
+%% parser and may not be up to date.
+
 definition
 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% Top level syntax.
 
-module Nix
+module Main
 imports Nix-Exprs Nix-Layout
 
 
@@ -38,6 +41,7 @@ exports
     "with" Expr ";" Expr -> Expr {cons("With")}
 
     "rec" "{" Bind* "}" -> Expr {cons("Rec")}
+    "let" Bind* "in" Expr -> Expr {cons("Let")}
     "let" "{" Bind* "}" -> Expr {cons("LetRec")}
     "{" Bind* "}" -> Expr {cons("Attrs")}
 
@@ -102,7 +106,8 @@ exports
 
     [0-9]+ -> Int
 
-    "\"" ~[\n\"]* "\"" -> Str
+    "\"" (~[\"\\] | ("\\" ~[]) )* "\"" -> Str
+    "''" (~[\"\\] | ("\\" ~[]) )* "''" -> Str
 
     [a-zA-Z0-9\.\_\-\+]* ("/"[a-zA-Z0-9\.\_\-\+]+)+ -> Path
 

src/libexpr/nixexpr-ast.def

@@ -3,8 +3,7 @@ init initNixExprHelpers
 Pos | string int int | Pos |
 NoPos | | Pos |
 
-Function | ATermList Expr Pos | Expr |
-Function1 | string Expr Pos | Expr |
+Function | Pattern Expr Pos | Expr |
 Assert | Expr Expr Pos | Expr |
 With | Expr Expr Pos | Expr |
 If | Expr Expr Expr | Expr |
@@ -24,9 +23,41 @@ Call | Expr Expr | Expr |
 Select | Expr string | Expr |
 Var | string | Expr |
 Int | int | Expr |
-Str | string | Expr |
+
+# Strings in the evaluator carry a so-called `context' (the ATermList)
+# which is a list of strings representing store paths.  This is to
+# allow users to write things like
+#
+#   "--with-freetype2-library=" + freetype + "/lib"
+#
+# where `freetype' is a derivation (or a source to be copied to the
+# store).  If we just concatenated the strings without keeping track
+# of the referenced store paths, then if the string is used as a
+# derivation attribute, the derivation will not have the correct
+# dependencies in its inputDrvs and inputSrcs.
+#
+# The semantics of the context is as follows: when a string with
+# context C is used as a derivation attribute, then the derivations in
+# C will be added to the inputDrvs of the derivation, and the other
+# store paths in C will be added to the inputSrcs of the derivations.
+#
+# For canonicity, the store paths should be in sorted order.
+Str | string ATermList | Expr |
+Str | string | Expr | ObsoleteStr
+
+# Internal to the parser, doesn't occur in ASTs.
+IndStr | string | Expr |
+
+# A path is a reference to a file system object that is to be copied
+# to the Nix store when used as a derivation attribute.  When it is
+# concatenated to a string (i.e., `str + path'), it is also copied and
+# the resulting store path is concatenated to the string (with the
+# store path in the context).  If a string or path is concatenated to
+# a path (i.e., `path + str' or `path + path'), the result is a new
+# path (if the right-hand side is a string, the context must be
+# empty).
 Path | string | Expr |
-Uri | string | Expr |
+
 List | ATermList | Expr |
 BlackHole | | Expr |
 Undefined | | Expr |
@@ -35,26 +66,27 @@ PrimOp | int ATermBlob ATermList | Expr |
 Attrs | ATermList | Expr |
 Closed | Expr | Expr |
 Rec | ATermList ATermList | Expr |
-Bool | ATerm | Expr |
+Bool | ATermBool | Expr |
 Null | | Expr |
-Context | ATermList Expr | Expr |
 
 Bind | string Expr Pos | ATerm |
-Bind | string Expr | ATerm | Bind2
+BindAttrPath | ATermList Expr Pos | ATerm | # desugared during parsing
+Bind | string Expr | ATerm | ObsoleteBind
 Inherit | Expr ATermList Pos | ATerm |
 
 Scope | | Expr |
 
-Formal | string ValidValues DefaultValue | ATerm |
+VarPat | string | Pattern |
+AttrsPat | ATermList ATermBool | Pattern | # bool = `...'
+AtPat | Pattern Pattern | Pattern |
 
-ValidValues | ATermList | ValidValues |
-UnrestrictedValues | | ValidValues |
+Formal | string DefaultValue | ATerm |
 
 DefaultValue | Expr | DefaultValue |
 NoDefaultValue | | DefaultValue |
 
-True | | ATerm |
-False | | ATerm |
+True | | ATermBool |
+False | | ATermBool |
 
 PrimOpDef | int ATermBlob | ATerm |
 
@@ -62,3 +94,4 @@ AttrRHS | Expr Pos | ATerm |
 
 eTrue = makeBool(makeTrue())
 eFalse = makeBool(makeFalse())
+sOverrides = toATerm("__overrides")

src/libexpr/nixexpr.cc

@@ -6,6 +6,8 @@
 #include "nixexpr-ast.hh"
 #include "nixexpr-ast.cc"
 
+#include <cstdlib>
+
 
 namespace nix {
     
@@ -17,7 +19,7 @@ string showPos(ATerm pos)
     if (matchNoPos(pos)) return "undefined position";
     if (!matchPos(pos, path, line, column))
         throw badTerm("position expected", pos);
-    return (format("`%1%', line %2%") % aterm2String(path) % line).str();
+    return (format("`%1%:%2%:%3%'") % aterm2String(path) % line % column).str();
 }
     
 
@@ -54,7 +56,7 @@ void queryAllAttrs(Expr e, ATermMap & attrs, bool withPos)
 {
     ATermList bnds;
     if (!matchAttrs(e, bnds))
-        throw TypeError("attribute set expected");
+        throw TypeError(format("value is %1% while an attribute set was expected") % showType(e));
 
     for (ATermIterator i(bnds); i; ++i) {
         ATerm name;
@@ -77,7 +79,7 @@ Expr queryAttr(Expr e, const string & name, ATerm & pos)
 {
     ATermList bnds;
     if (!matchAttrs(e, bnds))
-        throw TypeError("attribute set expected");
+        throw TypeError(format("value is %1% while an attribute set was expected") % showType(e));
 
     for (ATermIterator i(bnds); i; ++i) {
         ATerm name2, pos2;
@@ -108,6 +110,31 @@ Expr makeAttrs(const ATermMap & attrs)
 }
 
 
+static void varsBoundByPattern(ATermMap & map, Pattern pat)
+{
+    ATerm name;
+    ATermList formals;
+    Pattern pat1, pat2;
+    ATermBool ellipsis;
+    /* Use makeRemoved() so that it can be used directly in
+       substitute(). */
+    if (matchVarPat(pat, name))
+        map.set(name, makeRemoved());
+    else if (matchAttrsPat(pat, formals, ellipsis)) { 
+        for (ATermIterator i(formals); i; ++i) {
+            ATerm d1;
+            if (!matchFormal(*i, name, d1)) abort();
+            map.set(name, makeRemoved());
+        }
+    }
+    else if (matchAtPat(pat, pat1, pat2)) {
+        varsBoundByPattern(map, pat1);
+        varsBoundByPattern(map, pat2);
+    }
+    else abort();
+}
+
+
 Expr substitute(const Substitution & subs, Expr e)
 {
     checkInterrupt();
@@ -133,27 +160,17 @@ Expr substitute(const Substitution & subs, Expr e)
 
     /* In case of a function, filter out all variables bound by this
        function. */
-    ATermList formals;
+    Pattern pat;
     ATerm body;
-    if (matchFunction(e, formals, body, pos)) {
-        ATermMap map(ATgetLength(formals));
-        for (ATermIterator i(formals); i; ++i) {
-            ATerm d1, d2;
-            if (!matchFormal(*i, name, d1, d2)) abort();
-            map.set(name, makeRemoved());
-        }
+    if (matchFunction(e, pat, body, pos)) {
+        ATermMap map(16);
+        varsBoundByPattern(map, pat);
         Substitution subs2(&subs, &map);
         return makeFunction(
-            (ATermList) substitute(subs2, (ATerm) formals),
+            (Pattern) substitute(subs2, (Expr) pat),
             substitute(subs2, body), pos);
     }
 
-    if (matchFunction1(e, name, body, pos)) {
-        ATermMap map(1);
-        map.set(name, makeRemoved());
-        return makeFunction1(name, substitute(Substitution(&subs, &map), body), pos);
-    }
-        
     /* Idem for a mutually recursive attribute set. */
     ATermList rbnds, nrbnds;
     if (matchRec(e, rbnds, nrbnds)) {
@@ -211,38 +228,25 @@ static void checkVarDefs2(set<Expr> & done, const ATermMap & defs, Expr e)
     done.insert(e);
     
     ATerm name, pos, value;
-    ATermList formals;
     ATerm with, body;
     ATermList rbnds, nrbnds;
+    Pattern pat;
 
-    if (matchVar(e, name)) {
+    /* Closed terms don't have free variables, so we don't have to
+       check by definition. */
+    if (matchClosed(e, value)) return;
+    
+    else if (matchVar(e, name)) {
         if (!defs.get(name))
             throw EvalError(format("undefined variable `%1%'")
                 % aterm2String(name));
     }
 
-    else if (matchFunction(e, formals, body, pos)) {
+    else if (matchFunction(e, pat, body, pos)) {
         ATermMap defs2(defs);
-        for (ATermIterator i(formals); i; ++i) {
-            ATerm d1, d2;
-            if (!matchFormal(*i, name, d1, d2)) abort();
-            defs2.set(name, (ATerm) ATempty);
-        }
-        for (ATermIterator i(formals); i; ++i) {
-            ATerm valids, deflt;
-            set<Expr> done2;
-            if (!matchFormal(*i, name, valids, deflt)) abort();
-            checkVarDefs2(done, defs, valids);
-            checkVarDefs2(done2, defs2, deflt);
-        }
-        set<Expr> done2;
-        checkVarDefs2(done2, defs2, body);
-    }
-        
-    else if (matchFunction1(e, name, body, pos)) {
-        ATermMap defs2(defs);
-        defs2.set(name, (ATerm) ATempty);
+        varsBoundByPattern(defs2, pat);
         set<Expr> done2;
+        checkVarDefs2(done2, defs2, pat);
         checkVarDefs2(done2, defs2, body);
     }
         
@@ -287,41 +291,102 @@ void checkVarDefs(const ATermMap & defs, Expr e)
 }
 
 
+struct Canonicalise : TermFun
+{
+    ATerm operator () (ATerm e)
+    {
+        /* Remove position info. */
+        ATerm path;
+        int line, column;
+        if (matchPos(e, path, line, column))
+            return makeNoPos();
+
+        /* Sort attribute sets. */
+        ATermList _;
+        if (matchAttrs(e, _)) {
+            ATermMap attrs;
+            queryAllAttrs(e, attrs);
+            StringSet names;
+            for (ATermMap::const_iterator i = attrs.begin(); i != attrs.end(); ++i)
+                names.insert(aterm2String(i->key));
+
+            ATermList attrs2 = ATempty;
+            for (StringSet::reverse_iterator i = names.rbegin(); i != names.rend(); ++i)
+                attrs2 = ATinsert(attrs2,
+                    makeBind(toATerm(*i), attrs.get(toATerm(*i)), makeNoPos()));
+
+            return makeAttrs(attrs2);
+        }
+        
+        return e;
+    }
+};
+
+
+Expr canonicaliseExpr(Expr e)
+{
+    Canonicalise canonicalise;
+    return bottomupRewrite(canonicalise, e);
+}
+
+
 Expr makeBool(bool b)
 {
     return b ? eTrue : eFalse;
 }
 
 
+bool matchStr(Expr e, string & s, PathSet & context)
+{
+    ATermList l;
+    ATerm s_;
+
+    if (!matchStr(e, s_, l)) return false;
+
+    s = aterm2String(s_);
+
+    for (ATermIterator i(l); i; ++i)
+        context.insert(aterm2String(*i));
+
+    return true;
+}
+
+
+Expr makeStr(const string & s, const PathSet & context)
+{
+    return makeStr(toATerm(s), toATermList(context));
+}
+
+
 string showType(Expr e)
 {
-    ATerm t1, t2, t3;
+    ATerm t1, t2;
     ATermList l1;
     ATermBlob b1;
     int i1;
-    if (matchStr(e, t1)) return "a string";
+    Pattern p1;
+    if (matchStr(e, t1, l1)) return "a string";
     if (matchPath(e, t1)) return "a path";
-    if (matchUri(e, t1)) return "a path";
     if (matchNull(e)) return "null";
     if (matchInt(e, i1)) return "an integer";
     if (matchBool(e, t1)) return "a boolean";
-    if (matchFunction(e, l1, t1, t2)) return "a function";
-    if (matchFunction1(e, t1, t2, t3)) return "a function";
+    if (matchFunction(e, p1, t1, t2)) return "a function";
     if (matchAttrs(e, l1)) return "an attribute set";
     if (matchList(e, l1)) return "a list";
     if (matchPrimOp(e, i1, b1, l1)) return "a partially applied built-in function";
-    if (matchContext(e, l1, t1)) return "a context containing " + showType(t1);
     return "an unknown type";
 }
 
 
 string showValue(Expr e)
 {
-    ATerm s;
+    PathSet context;
+    string s;
+    ATerm s2;
     int i;
-    if (matchStr(e, s)) {
-        string t = aterm2String(s), u;
-        for (string::iterator i = t.begin(); i != t.end(); ++i)
+    if (matchStr(e, s, context)) {
+        string u;
+        for (string::iterator i = s.begin(); i != s.end(); ++i)
             if (*i == '\"' || *i == '\\') u += "\\" + *i;
             else if (*i == '\n') u += "\\n";
             else if (*i == '\r') u += "\\r";
@@ -329,8 +394,7 @@ string showValue(Expr e)
             else u += *i;
         return "\"" + u + "\"";
     }
-    if (matchPath(e, s)) return aterm2String(s);
-    if (matchUri(e, s)) return aterm2String(s);
+    if (matchPath(e, s2)) return aterm2String(s2);
     if (matchNull(e)) return "null";
     if (matchInt(e, i)) return (format("%1%") % i).str();
     if (e == eTrue) return "true";

src/libexpr/nixexpr.hh

@@ -11,7 +11,9 @@ namespace nix {
 
 
 MakeError(EvalError, Error)
+MakeError(ParseError, Error)
 MakeError(AssertionError, EvalError)
+MakeError(ThrownError, AssertionError)
 MakeError(Abort, EvalError)
 MakeError(TypeError, EvalError)
 
@@ -20,11 +22,10 @@ MakeError(TypeError, EvalError)
    property of the ATerm library allows us to implement caching of
    normals forms efficiently. */
 typedef ATerm Expr;
-
 typedef ATerm DefaultValue;
-typedef ATerm ValidValues;
-
 typedef ATerm Pos;
+typedef ATerm Pattern;
+typedef ATerm ATermBool;
 
 
 /* A STL vector of ATerms.  Should be used with great care since it's
@@ -71,6 +72,7 @@ struct TermFun
 };
 ATerm bottomupRewrite(TermFun & f, ATerm e);
 
+
 /* Query all attributes in an attribute set expression.  The
    expression must be in normal form. */
 void queryAllAttrs(Expr e, ATermMap & attrs, bool withPos = false);
@@ -83,16 +85,33 @@ Expr queryAttr(Expr e, const string & name, ATerm & pos);
 /* Create an attribute set expression from an Attrs value. */
 Expr makeAttrs(const ATermMap & attrs);
 
+
 /* Perform a set of substitutions on an expression. */
 Expr substitute(const Substitution & subs, Expr e);
 
+
 /* Check whether all variables are defined in the given expression.
    Throw an exception if this isn't the case. */
 void checkVarDefs(const ATermMap & def, Expr e);
 
+
+/* Canonicalise a Nix expression by sorting attributes and removing
+   location information. */
+Expr canonicaliseExpr(Expr e);
+
+
 /* Create an expression representing a boolean. */
 Expr makeBool(bool b);
 
+
+/* Manipulation of Str() nodes.  Note: matchStr() does not clear
+   context!  */
+bool matchStr(Expr e, string & s, PathSet & context);
+
+Expr makeStr(const string & s, const PathSet & context = PathSet());
+
+
+/* Showing types, values. */
 string showType(Expr e);
 
 string showValue(Expr e);

src/libexpr/normal-forms.cc

@@ -0,0 +1,64 @@
+#include "eval.hh"
+#include "util.hh"
+#include "globals.hh"
+#include "serialise.hh"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+namespace nix {
+
+
+void EvalState::loadNormalForms()
+{
+    //    nixCacheFile = getEnv("NIX_CACHE_FILE", nixStateDir + "/reduce-cache");
+    nixCacheFile = getEnv("NIX_CACHE_FILE");
+    string loadFlag = getEnv("NIX_CACHE_FILE_LOAD", "1");
+
+    if(nixCacheFile == "" || loadFlag == "")
+        return;
+    if(!pathExists(nixCacheFile))
+        return;
+
+    printMsg(lvlInfo, format("Load cache: ..."));
+    try {
+        int fd = open(nixCacheFile.c_str(), O_RDONLY);
+        if (fd == -1)
+            throw SysError(format("opening file `%1%'") % nixCacheFile);
+        AutoCloseFD auto_fd = fd;
+
+        FdSource source = fd;
+        normalForms = readATermMap(source);
+    } catch (Error & e) {
+        e.addPrefix(format("Cannot load cached reduce operations from %1%:\n") % nixCacheFile);
+        throw;
+    }
+    printMsg(lvlInfo, format("Load cache: end"));
+}
+
+void EvalState::saveNormalForms()
+{
+    string saveFlag = getEnv("NIX_CACHE_FILE_SAVE", "");
+
+    if(nixCacheFile == "" || saveFlag == "")
+        return;
+
+    printMsg(lvlInfo, format("Save cache: ..."));
+    try {
+        int fd = open(nixCacheFile.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
+        if (fd == -1)
+            throw SysError(format("opening file `%1%'") % nixCacheFile);
+        AutoCloseFD auto_fd = fd;
+
+        FdSink sink = fd;
+        writeATermMap(normalForms, sink);
+    } catch (Error & e) {
+        e.addPrefix(format("Cannot save cached reduce operations to %1%:\n") % nixCacheFile);
+        throw;
+    }
+    printMsg(lvlInfo, format("Save cache: end"));
+}
+
+
+}