downloader: when retry but can't resume, retry the whole file

(cherry picked from commit 2c692a3b14)

.dir-locals.el

@@ -13,4 +13,5 @@
   (eval . (c-set-offset 'arglist-cont-nonempty '+))
   (eval . (c-set-offset 'substatement-open 0))
   (eval . (c-set-offset 'access-label '-))
+  (eval . (c-set-offset 'inlambda 0))
   )))

.github/workflows/test.yml

@@ -0,0 +1,14 @@
+name: "Test"
+on:
+  pull_request:
+  push:
+jobs:
+  tests:
+    strategy:
+      matrix:
+        os: [ubuntu-18.04, macos]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2
+    - uses: cachix/install-nix-action@v8
+    - run: nix-build release.nix --arg nix '{ outPath = ./.; revCount = 123; shortRev = "abcdefgh"; }' --arg systems '[ builtins.currentSystem ]' -A installerScript -A perlBindings

.gitignore

@@ -4,9 +4,10 @@ perl/Makefile.config
 # /
 /aclocal.m4
 /autom4te.cache
+/precompiled-headers.h.gch
+/precompiled-headers.h.pch
 /config.*
 /configure
-/nix.spec
 /stamp-h1
 /svn-revision
 /libtool
@@ -46,7 +47,7 @@ perl/Makefile.config
 /src/libexpr/nix.tbl
 
 # /src/libstore/
-/src/libstore/*.gen.hh
+*.gen.*
 
 /src/nix/nix
 
@@ -84,6 +85,7 @@ perl/Makefile.config
 /tests/restricted-innocent
 /tests/shell
 /tests/shell.drv
+/tests/config.nix
 
 # /tests/lang/
 /tests/lang/*.out
@@ -117,3 +119,5 @@ GPATH
 GRTAGS
 GSYMS
 GTAGS
+
+nix-rust/target

.travis.yml

@@ -1,2 +1,8 @@
-os: osx
-script: ./tests/install-darwin.sh
+matrix:
+  include:
+    - language: osx
+      script: ./tests/install-darwin.sh
+    - language: nix
+      script: nix-build release.nix -A build.x86_64-linux
+notifications:
+  email: false

.version

@@ -1 +1 @@
-2.3
+2.4

Makefile

@@ -1,5 +1,7 @@
 makefiles = \
+  mk/precompiled-headers.mk \
   local.mk \
+  nix-rust/local.mk \
   src/libutil/local.mk \
   src/libstore/local.mk \
   src/libmain/local.mk \
@@ -15,15 +17,16 @@ makefiles = \
   tests/local.mk \
   tests/plugins/local.mk
 
-GLOBAL_CXXFLAGS += -g -Wall -include config.h
-
 -include Makefile.config
 
 OPTIMIZE = 1
 
 ifeq ($(OPTIMIZE), 1)
-  GLOBAL_CFLAGS += -O3
   GLOBAL_CXXFLAGS += -O3
+else
+  GLOBAL_CXXFLAGS += -O0
 endif
 
 include mk/lib.mk
+
+GLOBAL_CXXFLAGS += -g -Wall -include config.h -std=c++17

Makefile.config.in

@@ -5,10 +5,11 @@ CC = @CC@
 CFLAGS = @CFLAGS@
 CXX = @CXX@
 CXXFLAGS = @CXXFLAGS@
+LDFLAGS = @LDFLAGS@
 ENABLE_S3 = @ENABLE_S3@
 HAVE_SODIUM = @HAVE_SODIUM@
-HAVE_READLINE = @HAVE_READLINE@
 HAVE_SECCOMP = @HAVE_SECCOMP@
+BOOST_LDFLAGS = @BOOST_LDFLAGS@
 LIBCURL_LIBS = @LIBCURL_LIBS@
 OPENSSL_LIBS = @OPENSSL_LIBS@
 PACKAGE_NAME = @PACKAGE_NAME@
@@ -17,6 +18,7 @@ SODIUM_LIBS = @SODIUM_LIBS@
 LIBLZMA_LIBS = @LIBLZMA_LIBS@
 SQLITE3_LIBS = @SQLITE3_LIBS@
 LIBBROTLI_LIBS = @LIBBROTLI_LIBS@
+LIBARCHIVE_LIBS = @LIBARCHIVE_LIBS@
 EDITLINE_LIBS = @EDITLINE_LIBS@
 bash = @bash@
 bindir = @bindir@
@@ -35,6 +37,7 @@ prefix = @prefix@
 sandbox_shell = @sandbox_shell@
 storedir = @storedir@
 sysconfdir = @sysconfdir@
+system = @system@
 doc_generate = @doc_generate@
 xmllint = @xmllint@
 xsltproc = @xsltproc@

README.md

@@ -1,3 +1,5 @@
+[![Open Collective supporters](https://opencollective.com/nixos/tiers/supporter/badge.svg?label=Supporters&color=brightgreen)](https://opencollective.com/nixos)
+
 Nix, the purely functional package manager
 ------------------------------------------
 
@@ -7,16 +9,13 @@ appear with Nix.
 
 To find out more about the tool, usage and installation instructions, please
 read the manual, which is available on the Nix website at
-<http://nixos.org/nix/manual>.
+<https://nixos.org/nix/manual>.
 
 ## Contributing
 
-Take a look at the [Hacking Section](http://nixos.org/nix/manual/#chap-hacking)
+Take a look at the [Hacking Section](https://nixos.org/nix/manual/#chap-hacking)
 of the manual. It helps you to get started with building Nix from source.
 
 ## License
 
 Nix is released under the LGPL v2.1
-
-This product includes software developed by the OpenSSL Project for
-use in the [OpenSSL Toolkit](http://www.OpenSSL.org/).

configure.ac

@@ -1,4 +1,5 @@
 AC_INIT(nix, m4_esyscmd([bash -c "echo -n $(cat ./.version)$VERSION_SUFFIX"]))
+AC_CONFIG_MACRO_DIRS([m4])
 AC_CONFIG_SRCDIR(README.md)
 AC_CONFIG_AUX_DIR(config)
 
@@ -42,13 +43,25 @@ esac
 
 AC_MSG_RESULT($system)
 AC_SUBST(system)
-AC_DEFINE_UNQUOTED(SYSTEM, ["$system"], [platform identifier (`cpu-os')])
+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
 
 
+CFLAGS=
+CXXFLAGS=
+AC_PROG_CC
+AC_PROG_CXX
+AC_PROG_CPP
+
+AC_CHECK_TOOL([AR], [ar])
+
+# Use 64-bit file system calls so that we can support files > 2 GiB.
+AC_SYS_LARGEFILE
+
+
 # Solaris-specific stuff.
 AC_STRUCT_DIRENT_D_TYPE
 if test "$sys_name" = sunos; then
@@ -57,19 +70,6 @@ if test "$sys_name" = sunos; then
 fi
 
 
-CFLAGS=
-CXXFLAGS=
-AC_PROG_CC
-AC_PROG_CXX
-AC_PROG_CPP
-AX_CXX_COMPILE_STDCXX_17
-
-AC_CHECK_TOOL([AR], [ar])
-
-# Use 64-bit file system calls so that we can support files > 2 GiB.
-AC_SYS_LARGEFILE
-
-
 # Check for pubsetbuf.
 AC_MSG_CHECKING([for pubsetbuf])
 AC_LANG_PUSH(C++)
@@ -117,26 +117,15 @@ fi
 ])
 
 NEED_PROG(bash, bash)
-NEED_PROG(patch, patch)
 AC_PATH_PROG(xmllint, xmllint, false)
 AC_PATH_PROG(xsltproc, xsltproc, false)
 AC_PATH_PROG(flex, flex, false)
 AC_PATH_PROG(bison, bison, false)
-NEED_PROG(sed, sed)
-NEED_PROG(tar, tar)
-NEED_PROG(bzip2, bzip2)
-NEED_PROG(gzip, gzip)
-NEED_PROG(xz, xz)
 AC_PATH_PROG(dot, dot)
 AC_PATH_PROG(lsof, lsof, lsof)
 
 
-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 $cat))
-AC_SUBST(coreutils)
+AC_SUBST(coreutils, [$(dirname $(type -p cat))])
 
 
 AC_ARG_WITH(store-dir, AC_HELP_STRING([--with-store-dir=PATH],
@@ -145,7 +134,42 @@ AC_ARG_WITH(store-dir, AC_HELP_STRING([--with-store-dir=PATH],
 AC_SUBST(storedir)
 
 
-# Look for OpenSSL, a required dependency.
+# Look for boost, a required dependency.
+# Note that AX_BOOST_BASE only exports *CPP* BOOST_CPPFLAGS, no CXX flags,
+# and CPPFLAGS are not passed to the C++ compiler automatically.
+# Thus we append the returned CPPFLAGS to the CXXFLAGS here.
+AX_BOOST_BASE([1.66], [CXXFLAGS="$BOOST_CPPFLAGS $CXXFLAGS"], [AC_MSG_ERROR([Nix requires boost.])])
+# For unknown reasons, setting this directly in the ACTION-IF-FOUND above
+# ends up with LDFLAGS being empty, so we set it afterwards.
+LDFLAGS="$BOOST_LDFLAGS $LDFLAGS"
+
+# On some platforms, new-style atomics need a helper library
+AC_MSG_CHECKING(whether -latomic is needed)
+AC_LINK_IFELSE([AC_LANG_SOURCE([[
+#include <stdint.h>
+uint64_t v;
+int main() {
+    return (int)__atomic_load_n(&v, __ATOMIC_ACQUIRE);
+}]])], GCC_ATOMIC_BUILTINS_NEED_LIBATOMIC=no, GCC_ATOMIC_BUILTINS_NEED_LIBATOMIC=yes)
+AC_MSG_RESULT($GCC_ATOMIC_BUILTINS_NEED_LIBATOMIC)
+if test "x$GCC_ATOMIC_BUILTINS_NEED_LIBATOMIC" = xyes; then
+    LIBS="-latomic $LIBS"
+fi
+
+PKG_PROG_PKG_CONFIG
+
+AC_ARG_ENABLE(shared, AC_HELP_STRING([--enable-shared],
+  [Build shared libraries for Nix [default=yes]]),
+  shared=$enableval, shared=yes)
+if test "$shared" = yes; then
+  AC_SUBST(BUILD_SHARED_LIBS, 1, [Whether to build shared libraries.])
+else
+  AC_SUBST(BUILD_SHARED_LIBS, 0, [Whether to build shared libraries.])
+  PKG_CONFIG="$PKG_CONFIG --static"
+fi
+
+# Look for OpenSSL, a required dependency. FIXME: this is only (maybe)
+# used by S3BinaryCacheStore.
 PKG_CHECK_MODULES([OPENSSL], [libcrypto], [CXXFLAGS="$OPENSSL_CFLAGS $CXXFLAGS"])
 
 
@@ -154,17 +178,26 @@ AC_CHECK_LIB([bz2], [BZ2_bzWriteOpen], [true],
   [AC_MSG_ERROR([Nix requires libbz2, which is part of bzip2.  See https://web.archive.org/web/20180624184756/http://www.bzip.org/.])])
 AC_CHECK_HEADERS([bzlib.h], [true],
   [AC_MSG_ERROR([Nix requires libbz2, which is part of bzip2.  See https://web.archive.org/web/20180624184756/http://www.bzip.org/.])])
-
+# Checks for libarchive
+PKG_CHECK_MODULES([LIBARCHIVE], [libarchive >= 3.1.2], [CXXFLAGS="$LIBARCHIVE_CFLAGS $CXXFLAGS"])
 
 # Look for SQLite, a required dependency.
 PKG_CHECK_MODULES([SQLITE3], [sqlite3 >= 3.6.19], [CXXFLAGS="$SQLITE3_CFLAGS $CXXFLAGS"])
 
-
 # Look for libcurl, a required dependency.
 PKG_CHECK_MODULES([LIBCURL], [libcurl], [CXXFLAGS="$LIBCURL_CFLAGS $CXXFLAGS"])
 
 # Look for editline, a required dependency.
-PKG_CHECK_MODULES([EDITLINE], [libeditline], [CXXFLAGS="$EDITLINE_CFLAGS $CXXFLAGS"])
+# The the libeditline.pc file was added only in libeditline >= 1.15.2,
+# see https://github.com/troglobit/editline/commit/0a8f2ef4203c3a4a4726b9dd1336869cd0da8607,
+# but e.g. Ubuntu 16.04 has an older version, so we fall back to searching for
+# editline.h when the pkg-config approach fails.
+PKG_CHECK_MODULES([EDITLINE], [libeditline], [CXXFLAGS="$EDITLINE_CFLAGS $CXXFLAGS"], [
+  AC_CHECK_HEADERS([editline.h], [true],
+    [AC_MSG_ERROR([Nix requires libeditline; it was found neither via pkg-config nor its normal header.])])
+  AC_SEARCH_LIBS([readline read_history], [editline], [],
+    [AC_MSG_ERROR([Nix requires libeditline; it was not found via pkg-config, but via its header, but required functions do not work. Maybe it is too old? >= 1.14 is required.])])
+])
 
 # Look for libsodium, an optional dependency.
 PKG_CHECK_MODULES([SODIUM], [libsodium],
@@ -173,12 +206,15 @@ PKG_CHECK_MODULES([SODIUM], [libsodium],
    have_sodium=1], [have_sodium=])
 AC_SUBST(HAVE_SODIUM, [$have_sodium])
 
-
 # Look for liblzma, a required dependency.
 PKG_CHECK_MODULES([LIBLZMA], [liblzma], [CXXFLAGS="$LIBLZMA_CFLAGS $CXXFLAGS"])
 AC_CHECK_LIB([lzma], [lzma_stream_encoder_mt],
   [AC_DEFINE([HAVE_LZMA_MT], [1], [xz multithreaded compression support])])
 
+# Look for zlib, a required dependency.
+PKG_CHECK_MODULES([ZLIB], [zlib], [CXXFLAGS="$ZLIB_CFLAGS $CXXFLAGS"])
+AC_CHECK_HEADER([zlib.h],[:],[AC_MSG_ERROR([could not find the zlib.h header])])
+LDFLAGS="-lz $LDFLAGS"
 
 # Look for libbrotli{enc,dec}.
 PKG_CHECK_MODULES([LIBBROTLI], [libbrotlienc libbrotlidec], [CXXFLAGS="$LIBBROTLI_CFLAGS $CXXFLAGS"])
@@ -221,8 +257,8 @@ fi
 
 # Whether to use the Boehm garbage collector.
 AC_ARG_ENABLE(gc, AC_HELP_STRING([--enable-gc],
-  [enable garbage collection in the Nix expression evaluator (requires Boehm GC) [default=no]]),
-  gc=$enableval, gc=no)
+  [enable garbage collection in the Nix expression evaluator (requires Boehm GC) [default=yes]]),
+  gc=$enableval, gc=yes)
 if test "$gc" = yes; then
   PKG_CHECK_MODULES([BDW_GC], [bdw-gc])
   CXXFLAGS="$BDW_GC_CFLAGS $CXXFLAGS"
@@ -268,16 +304,6 @@ AC_ARG_WITH(sandbox-shell, AC_HELP_STRING([--with-sandbox-shell=PATH],
   sandbox_shell=$withval)
 AC_SUBST(sandbox_shell)
 
-AC_ARG_ENABLE(shared, AC_HELP_STRING([--enable-shared],
-  [Build shared libraries for Nix [default=yes]]),
-  shared=$enableval, shared=yes)
-if test "$shared" = yes; then
-  AC_SUBST(BUILD_SHARED_LIBS, 1, [Whether to build shared libraries.])
-else
-  AC_SUBST(BUILD_SHARED_LIBS, 0, [Whether to build shared libraries.])
-fi
-
-
 # Expand all variables in config.status.
 test "$prefix" = NONE && prefix=$ac_default_prefix
 test "$exec_prefix" = NONE && exec_prefix='${prefix}'

contrib/stack-collapse.py

@@ -0,0 +1,38 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i python3 -p python3 --pure
+
+# To be used with `--trace-function-calls` and `flamegraph.pl`.
+#
+# For example:
+#
+# nix-instantiate --trace-function-calls '<nixpkgs>' -A hello 2> nix-function-calls.trace
+# ./contrib/stack-collapse.py nix-function-calls.trace > nix-function-calls.folded
+# nix-shell -p flamegraph --run "flamegraph.pl nix-function-calls.folded > nix-function-calls.svg"
+
+import sys
+from pprint import pprint
+import fileinput
+
+stack = []
+timestack = []
+
+for line in fileinput.input():
+    components = line.strip().split(" ", 2)
+    if components[0] != "function-trace":
+        continue
+
+    direction = components[1]
+    components = components[2].rsplit(" ", 2)
+
+    loc = components[0]
+    _at = components[1]
+    time = int(components[2])
+
+    if direction == "entered":
+        stack.append(loc)
+        timestack.append(time)
+    elif direction == "exited":
+        dur = time - timestack.pop()
+        vst = ";".join(stack)
+        print(f"{vst} {dur}")
+        stack.pop()

corepkgs/config.nix.in

@@ -1,29 +1,13 @@
+# FIXME: remove this file?
 let
   fromEnv = var: def:
     let val = builtins.getEnv var; in
     if val != "" then val else def;
 in rec {
-  shell = "@bash@";
-  coreutils = "@coreutils@";
-  bzip2 = "@bzip2@";
-  gzip = "@gzip@";
-  xz = "@xz@";
-  tar = "@tar@";
-  tarFlags = "@tarFlags@";
-  tr = "@tr@";
   nixBinDir = fromEnv "NIX_BIN_DIR" "@bindir@";
   nixPrefix = "@prefix@";
   nixLibexecDir = fromEnv "NIX_LIBEXEC_DIR" "@libexecdir@";
   nixLocalstateDir = "@localstatedir@";
   nixSysconfDir = "@sysconfdir@";
   nixStoreDir = fromEnv "NIX_STORE_DIR" "@storedir@";
-
-  # If Nix is installed in the Nix store, then automatically add it as
-  # a dependency to the core packages. This ensures that they work
-  # properly in a chroot.
-  chrootDeps =
-    if dirOf nixPrefix == builtins.storeDir then
-      [ (builtins.storePath nixPrefix) ]
-    else
-      [ ];
 }

corepkgs/local.mk

@@ -1,4 +1,7 @@
-corepkgs_FILES = buildenv.nix unpack-channel.nix derivation.nix fetchurl.nix imported-drv-to-derivation.nix
+corepkgs_FILES = \
+  unpack-channel.nix \
+  derivation.nix \
+  fetchurl.nix
 
 $(foreach file,config.nix $(corepkgs_FILES),$(eval $(call install-data-in,$(d)/$(file),$(datadir)/nix/corepkgs)))
 

corepkgs/unpack-channel.nix

@@ -1,43 +1,12 @@
-with import <nix/config.nix>;
-
-let
-
-  builder = builtins.toFile "unpack-channel.sh"
-    ''
-      mkdir $out
-      cd $out
-      xzpat="\.xz\$"
-      gzpat="\.gz\$"
-      if [[ "$src" =~ $xzpat ]]; then
-        ${xz} -d < $src | ${tar} xf - ${tarFlags}
-      elif [[ "$src" =~ $gzpat ]]; then
-        ${gzip} -d < $src | ${tar} xf - ${tarFlags}
-      else
-        ${bzip2} -d < $src | ${tar} xf - ${tarFlags}
-      fi
-      if [ * != $channelName ]; then
-        mv * $out/$channelName
-      fi
-      if [ -n "$binaryCacheURL" ]; then
-        mkdir $out/binary-caches
-        echo -n "$binaryCacheURL" > $out/binary-caches/$channelName
-      fi
-    '';
-
-in
-
-{ name, channelName, src, binaryCacheURL ? "" }:
+{ name, channelName, src }:
 
 derivation {
-  system = builtins.currentSystem;
-  builder = shell;
-  args = [ "-e" builder ];
-  inherit name channelName src binaryCacheURL;
+  builder = "builtin:unpack-channel";
 
-  PATH = "${nixBinDir}:${coreutils}";
+  system = "builtin";
+
+  inherit name channelName src;
 
   # No point in doing this remotely.
   preferLocalBuild = true;
-
-  inherit chrootDeps;
 }

doc/manual/advanced-topics/advanced-topics.xml

@@ -7,5 +7,8 @@
 <title>Advanced Topics</title>
 
 <xi:include href="distributed-builds.xml" />
+<xi:include href="cores-vs-jobs.xml" />
+<xi:include href="diff-hook.xml" />
+<xi:include href="post-build-hook.xml" />
 
 </part>

doc/manual/advanced-topics/cores-vs-jobs.xml

@@ -0,0 +1,121 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+      xmlns:xlink="http://www.w3.org/1999/xlink"
+      xmlns:xi="http://www.w3.org/2001/XInclude"
+      version="5.0"
+      xml:id="chap-tuning-cores-and-jobs">
+
+<title>Tuning Cores and Jobs</title>
+
+<para>Nix has two relevant settings with regards to how your CPU cores
+will be utilized: <xref linkend="conf-cores" /> and
+<xref linkend="conf-max-jobs" />. This chapter will talk about what
+they are, how they interact, and their configuration trade-offs.</para>
+
+<variablelist>
+  <varlistentry>
+    <term><xref linkend="conf-max-jobs" /></term>
+    <listitem><para>
+      Dictates how many separate derivations will be built at the same
+      time. If you set this to zero, the local machine will do no
+      builds. Nix will still substitute from binary caches, and build
+      remotely if remote builders are configured.
+    </para></listitem>
+  </varlistentry>
+  <varlistentry>
+    <term><xref linkend="conf-cores" /></term>
+    <listitem><para>
+      Suggests how many cores each derivation should use. Similar to
+      <command>make -j</command>.
+    </para></listitem>
+  </varlistentry>
+</variablelist>
+
+<para>The <xref linkend="conf-cores" /> setting determines the value of
+<envar>NIX_BUILD_CORES</envar>. <envar>NIX_BUILD_CORES</envar> is equal
+to <xref linkend="conf-cores" />, unless <xref linkend="conf-cores" />
+equals <literal>0</literal>, in which case <envar>NIX_BUILD_CORES</envar>
+will be the total number of cores in the system.</para>
+
+<para>The maximum number of consumed cores is a simple multiplication,
+<xref linkend="conf-max-jobs" /> * <envar>NIX_BUILD_CORES</envar>.</para>
+
+<para>The balance on how to set these two independent variables depends
+upon each builder's workload and hardware. Here are a few example
+scenarios on a machine with 24 cores:</para>
+
+<table>
+  <caption>Balancing 24 Build Cores</caption>
+  <thead>
+    <tr>
+      <th><xref linkend="conf-max-jobs" /></th>
+      <th><xref linkend="conf-cores" /></th>
+      <th><envar>NIX_BUILD_CORES</envar></th>
+      <th>Maximum Processes</th>
+      <th>Result</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td>1</td>
+      <td>24</td>
+      <td>24</td>
+      <td>24</td>
+      <td>
+        One derivation will be built at a time, each one can use 24
+        cores. Undersold if a job can’t use 24 cores.
+      </td>
+    </tr>
+
+    <tr>
+      <td>4</td>
+      <td>6</td>
+      <td>6</td>
+      <td>24</td>
+      <td>
+        Four derivations will be built at once, each given access to
+        six cores.
+      </td>
+    </tr>
+    <tr>
+      <td>12</td>
+      <td>6</td>
+      <td>6</td>
+      <td>72</td>
+      <td>
+        12 derivations will be built at once, each given access to six
+        cores. This configuration is over-sold. If all 12 derivations
+        being built simultaneously try to use all six cores, the
+        machine's performance will be degraded due to extensive context
+        switching between the 12 builds.
+      </td>
+    </tr>
+    <tr>
+      <td>24</td>
+      <td>1</td>
+      <td>1</td>
+      <td>24</td>
+      <td>
+        24 derivations can build at the same time, each using a single
+        core. Never oversold, but derivations which require many cores
+        will be very slow to compile.
+      </td>
+    </tr>
+    <tr>
+      <td>24</td>
+      <td>0</td>
+      <td>24</td>
+      <td>576</td>
+      <td>
+        24 derivations can build at the same time, each using all the
+        available cores of the machine. Very likely to be oversold,
+        and very likely to suffer context switches.
+      </td>
+    </tr>
+  </tbody>
+</table>
+
+<para>It is up to the derivations' build script to respect
+host's requested cores-per-build by following the value of the
+<envar>NIX_BUILD_CORES</envar> environment variable.</para>
+
+</chapter>

doc/manual/advanced-topics/diff-hook.xml

@@ -0,0 +1,205 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+      xmlns:xlink="http://www.w3.org/1999/xlink"
+      xmlns:xi="http://www.w3.org/2001/XInclude"
+      xml:id="chap-diff-hook"
+      version="5.0"
+      >
+
+<title>Verifying Build Reproducibility with <option linkend="conf-diff-hook">diff-hook</option></title>
+
+<subtitle>Check build reproducibility by running builds multiple times
+and comparing their results.</subtitle>
+
+<para>Specify a program with Nix's <xref linkend="conf-diff-hook" /> to
+compare build results when two builds produce different results. Note:
+this hook is only executed if the results are not the same, this hook
+is not used for determining if the results are the same.</para>
+
+<para>For purposes of demonstration, we'll use the following Nix file,
+<filename>deterministic.nix</filename> for testing:</para>
+
+<programlisting>
+let
+  inherit (import &lt;nixpkgs&gt; {}) runCommand;
+in {
+  stable = runCommand "stable" {} ''
+    touch $out
+  '';
+
+  unstable = runCommand "unstable" {} ''
+    echo $RANDOM > $out
+  '';
+}
+</programlisting>
+
+<para>Additionally, <filename>nix.conf</filename> contains:
+
+<programlisting>
+diff-hook = /etc/nix/my-diff-hook
+run-diff-hook = true
+</programlisting>
+
+where <filename>/etc/nix/my-diff-hook</filename> is an executable
+file containing:
+
+<programlisting>
+#!/bin/sh
+exec &gt;&amp;2
+echo "For derivation $3:"
+/run/current-system/sw/bin/diff -r "$1" "$2"
+</programlisting>
+
+</para>
+
+<para>The diff hook is executed by the same user and group who ran the
+build. However, the diff hook does not have write access to the store
+path just built.</para>
+
+<section>
+  <title>
+    Spot-Checking Build Determinism
+  </title>
+
+  <para>
+    Verify a path which already exists in the Nix store by passing
+    <option>--check</option> to the build command.
+  </para>
+
+  <para>If the build passes and is deterministic, Nix will exit with a
+  status code of 0:</para>
+
+  <screen>
+$ nix-build ./deterministic.nix -A stable
+these derivations will be built:
+  /nix/store/z98fasz2jqy9gs0xbvdj939p27jwda38-stable.drv
+building '/nix/store/z98fasz2jqy9gs0xbvdj939p27jwda38-stable.drv'...
+/nix/store/yyxlzw3vqaas7wfp04g0b1xg51f2czgq-stable
+
+$ nix-build ./deterministic.nix -A stable --check
+checking outputs of '/nix/store/z98fasz2jqy9gs0xbvdj939p27jwda38-stable.drv'...
+/nix/store/yyxlzw3vqaas7wfp04g0b1xg51f2czgq-stable
+</screen>
+
+  <para>If the build is not deterministic, Nix will exit with a status
+  code of 1:</para>
+
+  <screen>
+$ nix-build ./deterministic.nix -A unstable
+these derivations will be built:
+  /nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv
+building '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv'...
+/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable
+
+$ nix-build ./deterministic.nix -A unstable --check
+checking outputs of '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv'...
+error: derivation '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv' may not be deterministic: output '/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable' differs
+</screen>
+
+<para>In the Nix daemon's log, we will now see:
+<screen>
+For derivation /nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv:
+1c1
+&lt; 8108
+---
+&gt; 30204
+</screen>
+</para>
+
+  <para>Using <option>--check</option> with <option>--keep-failed</option>
+  will cause Nix to keep the second build's output in a special,
+  <literal>.check</literal> path:</para>
+
+  <screen>
+$ nix-build ./deterministic.nix -A unstable --check --keep-failed
+checking outputs of '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv'...
+note: keeping build directory '/tmp/nix-build-unstable.drv-0'
+error: derivation '/nix/store/cgl13lbj1w368r5z8gywipl1ifli7dhk-unstable.drv' may not be deterministic: output '/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable' differs from '/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable.check'
+</screen>
+
+  <para>In particular, notice the
+  <literal>/nix/store/krpqk0l9ib0ibi1d2w52z293zw455cap-unstable.check</literal>
+  output. Nix has copied the build results to that directory where you
+  can examine it.</para>
+
+  <note xml:id="check-dirs-are-unregistered">
+    <title><literal>.check</literal> paths are not registered store paths</title>
+
+    <para>Check paths are not protected against garbage collection,
+    and this path will be deleted on the next garbage collection.</para>
+
+    <para>The path is guaranteed to be alive for the duration of
+    <xref linkend="conf-diff-hook" />'s execution, but may be deleted
+    any time after.</para>
+
+    <para>If the comparison is performed as part of automated tooling,
+    please use the diff-hook or author your tooling to handle the case
+    where the build was not deterministic and also a check path does
+    not exist.</para>
+  </note>
+
+  <para>
+    <option>--check</option> is only usable if the derivation has
+    been built on the system already. If the derivation has not been
+    built Nix will fail with the error:
+    <screen>
+error: some outputs of '/nix/store/hzi1h60z2qf0nb85iwnpvrai3j2w7rr6-unstable.drv' are not valid, so checking is not possible
+</screen>
+
+    Run the build without <option>--check</option>, and then try with
+    <option>--check</option> again.
+  </para>
+</section>
+
+<section>
+  <title>
+    Automatic and Optionally Enforced Determinism Verification
+  </title>
+
+  <para>
+    Automatically verify every build at build time by executing the
+    build multiple times.
+  </para>
+
+  <para>
+    Setting <xref linkend="conf-repeat" /> and
+    <xref linkend="conf-enforce-determinism" /> in your
+    <filename>nix.conf</filename> permits the automated verification
+    of every build Nix performs.
+  </para>
+
+  <para>
+    The following configuration will run each build three times, and
+    will require the build to be deterministic:
+
+    <programlisting>
+enforce-determinism = true
+repeat = 2
+</programlisting>
+  </para>
+
+  <para>
+    Setting <xref linkend="conf-enforce-determinism" /> to false as in
+    the following configuration will run the build multiple times,
+    execute the build hook, but will allow the build to succeed even
+    if it does not build reproducibly:
+
+    <programlisting>
+enforce-determinism = false
+repeat = 1
+</programlisting>
+  </para>
+
+  <para>
+    An example output of this configuration:
+    <screen>
+$ nix-build ./test.nix -A unstable
+these derivations will be built:
+  /nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv
+building '/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv' (round 1/2)...
+building '/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv' (round 2/2)...
+output '/nix/store/6xg356v9gl03hpbbg8gws77n19qanh02-unstable' of '/nix/store/ch6llwpr2h8c3jmnf3f2ghkhx59aa97f-unstable.drv' differs from '/nix/store/6xg356v9gl03hpbbg8gws77n19qanh02-unstable.check' from previous round
+/nix/store/6xg356v9gl03hpbbg8gws77n19qanh02-unstable
+</screen>
+  </para>
+</section>
+</chapter>

doc/manual/advanced-topics/distributed-builds.xml

@@ -184,4 +184,7 @@ to be included. (This is the default.)</para>
 the option <link linkend='conf-builders-use-substitutes'><literal>builders-use-substitutes</literal></link>
 in your local <filename>nix.conf</filename>.</para>
 
+<para>To build only on remote builders and disable building on the local machine,
+you can use the option <option>--max-jobs 0</option>.</para>
+
 </chapter>

doc/manual/advanced-topics/post-build-hook.xml

@@ -0,0 +1,160 @@
+<chapter xmlns="http://docbook.org/ns/docbook"
+      xmlns:xlink="http://www.w3.org/1999/xlink"
+      xmlns:xi="http://www.w3.org/2001/XInclude"
+      xml:id="chap-post-build-hook"
+      version="5.0"
+      >
+
+<title>Using the <option linkend="conf-post-build-hook">post-build-hook</option></title>
+<subtitle>Uploading to an S3-compatible binary cache after each build</subtitle>
+
+
+<section xml:id="chap-post-build-hook-caveats">
+  <title>Implementation Caveats</title>
+  <para>Here we use the post-build hook to upload to a binary cache.
+  This is a simple and working example, but it is not suitable for all
+  use cases.</para>
+
+  <para>The post build hook program runs after each executed build,
+  and blocks the build loop. The build loop exits if the hook program
+  fails.</para>
+
+  <para>Concretely, this implementation will make Nix slow or unusable
+  when the internet is slow or unreliable.</para>
+
+  <para>A more advanced implementation might pass the store paths to a
+  user-supplied daemon or queue for processing the store paths outside
+  of the build loop.</para>
+</section>
+
+<section>
+  <title>Prerequisites</title>
+
+  <para>
+    This tutorial assumes you have configured an S3-compatible binary cache
+    according to the instructions at
+    <xref linkend="ssec-s3-substituter-authenticated-writes" />, and
+    that the <literal>root</literal> user's default AWS profile can
+    upload to the bucket.
+  </para>
+</section>
+
+<section>
+  <title>Set up a Signing Key</title>
+  <para>Use <command>nix-store --generate-binary-cache-key</command> to
+  create our public and private signing keys. We will sign paths
+  with the private key, and distribute the public key for verifying
+  the authenticity of the paths.</para>
+
+  <screen>
+# nix-store --generate-binary-cache-key example-nix-cache-1 /etc/nix/key.private /etc/nix/key.public
+# cat /etc/nix/key.public
+example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM=
+</screen>
+
+<para>Then, add the public key and the cache URL to your
+<filename>nix.conf</filename>'s <xref linkend="conf-trusted-public-keys" />
+and <xref linkend="conf-substituters" /> like:</para>
+
+<programlisting>
+substituters = https://cache.nixos.org/ s3://example-nix-cache
+trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= example-nix-cache-1:1/cKDz3QCCOmwcztD2eV6Coggp6rqc9DGjWv7C0G+rM=
+</programlisting>
+
+<para>we will restart the Nix daemon a later step.</para>
+</section>
+
+<section>
+  <title>Implementing the build hook</title>
+  <para>Write the following script to
+  <filename>/etc/nix/upload-to-cache.sh</filename>:
+  </para>
+
+  <programlisting>
+#!/bin/sh
+
+set -eu
+set -f # disable globbing
+export IFS=' '
+
+echo "Signing paths" $OUT_PATHS
+nix sign-paths --key-file /etc/nix/key.private $OUT_PATHS
+echo "Uploading paths" $OUT_PATHS
+exec nix copy --to 's3://example-nix-cache' $OUT_PATHS
+</programlisting>
+
+  <note>
+    <title>Should <literal>$OUT_PATHS</literal> be quoted?</title>
+    <para>
+      The <literal>$OUT_PATHS</literal> variable is a space-separated
+      list of Nix store paths. In this case, we expect and want the
+      shell to perform word splitting to make each output path its
+      own argument to <command>nix sign-paths</command>. Nix guarantees
+      the paths will not contain any spaces, however a store path
+      might contain glob characters. The <command>set -f</command>
+      disables globbing in the shell.
+    </para>
+  </note>
+  <para>
+    Then make sure the hook program is executable by the <literal>root</literal> user:
+    <screen>
+# chmod +x /etc/nix/upload-to-cache.sh
+</screen></para>
+</section>
+
+<section>
+  <title>Updating Nix Configuration</title>
+
+  <para>Edit <filename>/etc/nix/nix.conf</filename> to run our hook,
+  by adding the following configuration snippet at the end:</para>
+
+  <programlisting>
+post-build-hook = /etc/nix/upload-to-cache.sh
+</programlisting>
+
+<para>Then, restart the <command>nix-daemon</command>.</para>
+</section>
+
+<section>
+  <title>Testing</title>
+
+  <para>Build any derivation, for example:</para>
+
+  <screen>
+$ nix-build -E '(import &lt;nixpkgs&gt; {}).writeText "example" (builtins.toString builtins.currentTime)'
+these derivations will be built:
+  /nix/store/s4pnfbkalzy5qz57qs6yybna8wylkig6-example.drv
+building '/nix/store/s4pnfbkalzy5qz57qs6yybna8wylkig6-example.drv'...
+running post-build-hook '/home/grahamc/projects/github.com/NixOS/nix/post-hook.sh'...
+post-build-hook: Signing paths /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
+post-build-hook: Uploading paths /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
+/nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
+</screen>
+
+  <para>Then delete the path from the store, and try substituting it from the binary cache:</para>
+  <screen>
+$ rm ./result
+$ nix-store --delete /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
+</screen>
+
+<para>Now, copy the path back from the cache:</para>
+<screen>
+$ nix store --realize /nix/store/ibcyipq5gf91838ldx40mjsp0b8w9n18-example
+copying path '/nix/store/m8bmqwrch6l3h8s0k3d673xpmipcdpsa-example from 's3://example-nix-cache'...
+warning: you did not specify '--add-root'; the result might be removed by the garbage collector
+/nix/store/m8bmqwrch6l3h8s0k3d673xpmipcdpsa-example
+</screen>
+</section>
+<section>
+  <title>Conclusion</title>
+  <para>
+    We now have a Nix installation configured to automatically sign and
+    upload every local build to a remote binary cache.
+  </para>
+
+  <para>
+    Before deploying this to production, be sure to consider the
+    implementation caveats in <xref linkend="chap-post-build-hook-caveats" />.
+  </para>
+</section>
+</chapter>

doc/manual/command-ref/conf-file.xml

@@ -1,7 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
 <refentry xmlns="http://docbook.org/ns/docbook"
           xmlns:xlink="http://www.w3.org/1999/xlink"
           xmlns:xi="http://www.w3.org/2001/XInclude"
-          xml:id="sec-conf-file">
+          xml:id="sec-conf-file"
+          version="5">
 
 <refmeta>
   <refentrytitle>nix.conf</refentrytitle>
@@ -236,8 +238,74 @@ false</literal>.</para>
     linkend='opt-cores'>--cores</option> command line switch and
     defaults to <literal>1</literal>.  The value <literal>0</literal>
     means that the builder should use all available CPU cores in the
-    system.</para></listitem>
+    system.</para>
 
+    <para>See also <xref linkend="chap-tuning-cores-and-jobs" />.</para></listitem>
+  </varlistentry>
+
+  <varlistentry xml:id="conf-diff-hook"><term><literal>diff-hook</literal></term>
+  <listitem>
+    <para>
+      Absolute path to an executable capable of diffing build results.
+      The hook executes if <xref linkend="conf-run-diff-hook" /> is
+      true, and the output of a build is known to not be the same.
+      This program is not executed to determine if two results are the
+      same.
+    </para>
+
+    <para>
+      The diff hook is executed by the same user and group who ran the
+      build. However, the diff hook does not have write access to the
+      store path just built.
+    </para>
+
+    <para>The diff hook program receives three parameters:</para>
+
+    <orderedlist>
+      <listitem>
+        <para>
+          A path to the previous build's results
+        </para>
+      </listitem>
+
+      <listitem>
+        <para>
+          A path to the current build's results
+        </para>
+      </listitem>
+
+      <listitem>
+        <para>
+          The path to the build's derivation
+        </para>
+      </listitem>
+
+      <listitem>
+        <para>
+          The path to the build's scratch directory. This directory
+          will exist only if the build was run with
+          <option>--keep-failed</option>.
+        </para>
+      </listitem>
+    </orderedlist>
+
+    <para>
+      The stderr and stdout output from the diff hook will not be
+      displayed to the user. Instead, it will print to the nix-daemon's
+      log.
+    </para>
+
+    <para>When using the Nix daemon, <literal>diff-hook</literal> must
+    be set in the <filename>nix.conf</filename> configuration file, and
+    cannot be passed at the command line.
+    </para>
+  </listitem>
+  </varlistentry>
+
+  <varlistentry xml:id="conf-enforce-determinism">
+    <term><literal>enforce-determinism</literal></term>
+
+    <listitem><para>See <xref linkend="conf-repeat" />.</para></listitem>
   </varlistentry>
 
   <varlistentry xml:id="conf-extra-sandbox-paths">
@@ -365,7 +433,7 @@ builtins.fetchurl {
   <varlistentry xml:id="conf-keep-env-derivations"><term><literal>keep-env-derivations</literal></term>
 
     <listitem><para>If <literal>false</literal> (default), derivations
-    are not stored in Nix user environments.  That is, the derivation
+    are not stored in Nix user environments.  That is, the derivations of
     any build-time-only dependencies may be garbage-collected.</para>
 
     <para>If <literal>true</literal>, when you add a Nix derivation to
@@ -415,8 +483,10 @@ builtins.fetchurl {
 
   <varlistentry xml:id="conf-max-free"><term><literal>max-free</literal></term>
 
-    <listitem><para>This option defines after how many free bytes to stop collecting
-    garbage once the <literal>min-free</literal> condition gets triggered.</para></listitem>
+    <listitem><para>When a garbage collection is triggered by the
+    <literal>min-free</literal> option, it stops as soon as
+    <literal>max-free</literal> bytes are available. The default is
+    infinity (i.e. delete all garbage).</para></listitem>
 
   </varlistentry>
 
@@ -431,7 +501,10 @@ builtins.fetchurl {
     regardless).  It can be
     overridden using the <option
     linkend='opt-max-jobs'>--max-jobs</option> (<option>-j</option>)
-    command line switch.</para></listitem>
+    command line switch.</para>
+
+    <para>See also <xref linkend="chap-tuning-cores-and-jobs" />.</para>
+    </listitem>
   </varlistentry>
 
   <varlistentry xml:id="conf-max-silent-time"><term><literal>max-silent-time</literal></term>
@@ -457,9 +530,11 @@ builtins.fetchurl {
   <varlistentry xml:id="conf-min-free"><term><literal>min-free</literal></term>
 
     <listitem>
-      <para>When the disk reaches <literal>min-free</literal> bytes of free disk space during a build, nix
-        will start to garbage-collection until <literal>max-free</literal> bytes are available on the disk.
-        A value of <literal>0</literal> (the default) means that this feature is disabled.</para>
+      <para>When free disk space in <filename>/nix/store</filename>
+      drops below <literal>min-free</literal> during a build, Nix
+      performs a garbage-collection until <literal>max-free</literal>
+      bytes are available or there is no more garbage.  A value of
+      <literal>0</literal> (the default) disables this feature.</para>
     </listitem>
 
   </varlistentry>
@@ -589,15 +664,71 @@ password <replaceable>my-password</replaceable>
 
   </varlistentry>
 
+  <varlistentry xml:id="conf-post-build-hook">
+    <term><literal>post-build-hook</literal></term>
+    <listitem>
+      <para>Optional. The path to a program to execute after each build.</para>
+
+      <para>This option is only settable in the global
+      <filename>nix.conf</filename>, or on the command line by trusted
+      users.</para>
+
+      <para>When using the nix-daemon, the daemon executes the hook as
+      <literal>root</literal>. If the nix-daemon is not involved, the
+      hook runs as the user executing the nix-build.</para>
+
+      <itemizedlist>
+        <listitem><para>The hook executes after an evaluation-time build.</para></listitem>
+        <listitem><para>The hook does not execute on substituted paths.</para></listitem>
+        <listitem><para>The hook's output always goes to the user's terminal.</para></listitem>
+        <listitem><para>If the hook fails, the build succeeds but no further builds execute.</para></listitem>
+        <listitem><para>The hook executes synchronously, and blocks other builds from progressing while it runs.</para></listitem>
+      </itemizedlist>
+
+      <para>The program executes with no arguments. The program's environment
+      contains the following environment variables:</para>
+
+      <variablelist>
+        <varlistentry>
+          <term><envar>DRV_PATH</envar></term>
+          <listitem>
+            <para>The derivation for the built paths.</para>
+            <para>Example:
+            <literal>/nix/store/5nihn1a7pa8b25l9zafqaqibznlvvp3f-bash-4.4-p23.drv</literal>
+            </para>
+          </listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><envar>OUT_PATHS</envar></term>
+          <listitem>
+            <para>Output paths of the built derivation, separated by a space character.</para>
+            <para>Example:
+            <literal>/nix/store/zf5lbh336mnzf1nlswdn11g4n2m8zh3g-bash-4.4-p23-dev
+            /nix/store/rjxwxwv1fpn9wa2x5ssk5phzwlcv4mna-bash-4.4-p23-doc
+            /nix/store/6bqvbzjkcp9695dq0dpl5y43nvy37pq1-bash-4.4-p23-info
+            /nix/store/r7fng3kk3vlpdlh2idnrbn37vh4imlj2-bash-4.4-p23-man
+            /nix/store/xfghy8ixrhz3kyy6p724iv3cxji088dx-bash-4.4-p23</literal>.
+            </para>
+          </listitem>
+        </varlistentry>
+      </variablelist>
+
+      <para>See <xref linkend="chap-post-build-hook" /> for an example
+      implementation.</para>
+
+    </listitem>
+  </varlistentry>
+
   <varlistentry xml:id="conf-repeat"><term><literal>repeat</literal></term>
 
     <listitem><para>How many times to repeat builds to check whether
     they are deterministic. The default value is 0. If the value is
     non-zero, every build is repeated the specified number of
     times. If the contents of any of the runs differs from the
-    previous ones, the build is rejected and the resulting store paths
-    are not registered as “valid” in Nix’s database.</para></listitem>
-
+    previous ones and <xref linkend="conf-enforce-determinism" /> is
+    true, the build is rejected and the resulting store paths are not
+    registered as “valid” in Nix’s database.</para></listitem>
   </varlistentry>
 
   <varlistentry xml:id="conf-require-sigs"><term><literal>require-sigs</literal></term>
@@ -628,6 +759,19 @@ password <replaceable>my-password</replaceable>
 
   </varlistentry>
 
+  <varlistentry xml:id="conf-run-diff-hook"><term><literal>run-diff-hook</literal></term>
+  <listitem>
+    <para>
+      If true, enable the execution of <xref linkend="conf-diff-hook" />.
+    </para>
+
+    <para>
+      When using the Nix daemon, <literal>run-diff-hook</literal> must
+      be set in the <filename>nix.conf</filename> configuration file,
+      and cannot be passed at the command line.
+    </para>
+  </listitem>
+  </varlistentry>
 
   <varlistentry xml:id="conf-sandbox"><term><literal>sandbox</literal></term>
 
@@ -729,6 +873,14 @@ password <replaceable>my-password</replaceable>
 
   </varlistentry>
 
+  <varlistentry xml:id="conf-stalled-download-timeout"><term><literal>stalled-download-timeout</literal></term>
+    <listitem>
+      <para>The timeout (in seconds) for receiving data from servers
+      during download. Nix cancels idle downloads after this timeout's
+      duration.</para>
+    </listitem>
+  </varlistentry>
+
   <varlistentry xml:id="conf-substituters"><term><literal>substituters</literal></term>
 
     <listitem><para>A list of URLs of substituters, separated by
@@ -784,6 +936,31 @@ requiredSystemFeatures = [ "kvm" ];
 
   </varlistentry>
 
+  <varlistentry xml:id="conf-tarball-ttl"><term><literal>tarball-ttl</literal></term>
+
+    <listitem>
+      <para>Default: <literal>3600</literal> seconds.</para>
+
+      <para>The number of seconds a downloaded tarball is considered
+      fresh. If the cached tarball is stale, Nix will check whether
+      it is still up to date using the ETag header. Nix will download
+      a new version if the ETag header is unsupported, or the
+      cached ETag doesn't match.
+      </para>
+
+      <para>Setting the TTL to <literal>0</literal> forces Nix to always
+      check if the tarball is up to date.</para>
+
+      <para>Nix caches tarballs in
+      <filename>$XDG_CACHE_HOME/nix/tarballs</filename>.</para>
+
+      <para>Files fetched via <envar>NIX_PATH</envar>,
+      <function>fetchGit</function>, <function>fetchMercurial</function>,
+      <function>fetchTarball</function>, and <function>fetchurl</function>
+      respect this TTL.
+      </para>
+    </listitem>
+  </varlistentry>
 
   <varlistentry xml:id="conf-timeout"><term><literal>timeout</literal></term>
 
@@ -804,6 +981,34 @@ requiredSystemFeatures = [ "kvm" ];
 
   </varlistentry>
 
+  <varlistentry xml:id="conf-trace-function-calls"><term><literal>trace-function-calls</literal></term>
+
+    <listitem>
+
+      <para>Default: <literal>false</literal>.</para>
+
+      <para>If set to <literal>true</literal>, the Nix evaluator will
+      trace every function call. Nix will print a log message at the
+      "vomit" level for every function entrance and function exit.</para>
+
+      <informalexample><screen>
+function-trace entered undefined position at 1565795816999559622
+function-trace exited undefined position at 1565795816999581277
+function-trace entered /nix/store/.../example.nix:226:41 at 1565795253249935150
+function-trace exited /nix/store/.../example.nix:226:41 at 1565795253249941684
+</screen></informalexample>
+
+      <para>The <literal>undefined position</literal> means the function
+      call is a builtin.</para>
+
+      <para>Use the <literal>contrib/stack-collapse.py</literal> script
+      distributed with the Nix source code to convert the trace logs
+      in to a format suitable for <command>flamegraph.pl</command>.</para>
+
+    </listitem>
+
+  </varlistentry>
+
   <varlistentry xml:id="conf-trusted-public-keys"><term><literal>trusted-public-keys</literal></term>
 
     <listitem><para>A whitespace-separated list of public keys. When

doc/manual/command-ref/env-common.xml

@@ -14,7 +14,8 @@
 <varlistentry><term><envar>IN_NIX_SHELL</envar></term>
 
   <listitem><para>Indicator that tells if the current environment was set up by
-  <command>nix-shell</command>.</para></listitem>
+  <command>nix-shell</command>.  Since Nix 2.0 the values are
+  <literal>"pure"</literal> and <literal>"impure"</literal></para></listitem>
 
 </varlistentry>
 
@@ -121,7 +122,7 @@ $ mount -o bind /mnt/otherdisk/nix /nix</screen>
 <varlistentry><term><envar>NIX_LOG_DIR</envar></term>
 
   <listitem><para>Overrides the location of the Nix log directory
-  (default <filename><replaceable>prefix</replaceable>/log/nix</filename>).</para></listitem>
+  (default <filename><replaceable>prefix</replaceable>/var/log/nix</filename>).</para></listitem>
 
 </varlistentry>
 

doc/manual/command-ref/nix-build.xml

@@ -30,6 +30,7 @@
       <replaceable>attrPath</replaceable>
     </arg>
     <arg><option>--no-out-link</option></arg>
+    <arg><option>--dry-run</option></arg>
     <arg>
       <group choice='req'>
         <arg choice='plain'><option>--out-link</option></arg>
@@ -98,6 +99,10 @@ also <xref linkend="sec-common-options" />.</phrase></para>
 
   </varlistentry>
 
+  <varlistentry><term><option>--dry-run</option></term>
+   <listitem><para>Show what store paths would be built or downloaded.</para></listitem>
+  </varlistentry>
+
   <varlistentry xml:id='opt-out-link'><term><option>--out-link</option> /
   <option>-o</option> <replaceable>outlink</replaceable></term>
 

doc/manual/command-ref/nix-channel.xml

@@ -31,12 +31,14 @@
 
 <refsection><title>Description</title>
 
-<para>A Nix channel is a mechanism that allows you to automatically stay
-up-to-date with a set of pre-built Nix expressions.  A Nix channel is
-just a URL that points to a place containing both a set of Nix
-expressions and a pointer to a binary cache.  <phrase
-condition="manual">See also <xref linkend="sec-channels"
-/>.</phrase></para>
+<para>A Nix channel is a mechanism that allows you to automatically
+stay up-to-date with a set of pre-built Nix expressions.  A Nix
+channel is just a URL that points to a place containing a set of Nix
+expressions.  <phrase condition="manual">See also <xref
+linkend="sec-channels" />.</phrase></para>
+      
+<para>To see the list of official NixOS channels, visit <link
+xlink:href="https://nixos.org/channels" />.</para>
 
 <para>This command has the following operations:
 
@@ -112,13 +114,13 @@ $ nix-env -iA nixpkgs.hello</screen>
 <para>You can revert channel updates using <option>--rollback</option>:</para>
 
 <screen>
-$ nix-instantiate --eval -E '(import &lt;nixpkgs> {}).lib.nixpkgsVersion'
+$ nix-instantiate --eval -E '(import &lt;nixpkgs> {}).lib.version'
 "14.04.527.0e935f1"
 
 $ nix-channel --rollback
 switching from generation 483 to 482
 
-$ nix-instantiate --eval -E '(import &lt;nixpkgs> {}).lib.nixpkgsVersion'
+$ nix-instantiate --eval -E '(import &lt;nixpkgs> {}).lib.version'
 "14.04.526.dbadfad"
 </screen>
 
@@ -172,18 +174,6 @@ following files:</para>
 
   </varlistentry>
 
-  <varlistentry><term><filename>binary-cache-url</filename></term>
-
-    <listitem><para>A file containing the URL to a binary cache (such
-    as <uri>https://cache.nixos.org</uri>). Nix will automatically
-    check this cache for pre-built binaries, if the user has
-    sufficient rights to add binary caches. For instance, in a
-    multi-user Nix setup, the binary caches provided by the channels
-    of the root user are used automatically, but caches corresponding
-    to the channels of non-root users are ignored.</para></listitem>
-
-  </varlistentry>
-
 </variablelist>
 
 </refsection>

doc/manual/command-ref/nix-env.xml

@@ -221,31 +221,53 @@ also <xref linkend="sec-common-options" />.</phrase></para>
 
   <varlistentry><term><filename>~/.nix-defexpr</filename></term>
 
-    <listitem><para>A directory that contains the default Nix
+    <listitem><para>The source for the default Nix
     expressions used by the <option>--install</option>,
     <option>--upgrade</option>, and <option>--query
-    --available</option> operations to obtain derivations.  The
+    --available</option> operations to obtain derivations. The
     <option>--file</option> option may be used to override this
     default.</para>
 
-    <para>The Nix expressions in this directory are combined into a
-    single 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>,
+    <para>If <filename>~/.nix-defexpr</filename> is a file,
+    it is loaded as a Nix expression. If the expression
+    is a set, it is used as the default Nix expression.
+    If the expression is a function, an empty set is passed
+    as argument and the return value is used as
+    the default Nix expression.</para>
+
+    <para>If <filename>~/.nix-defexpr</filename> is a directory
+    containing a <filename>default.nix</filename> file, that file
+    is loaded as in the above paragraph.</para>
+
+    <para>If <filename>~/.nix-defexpr</filename> is a directory without
+    a <filename>default.nix</filename> file, then its contents
+    (both files and subdirectories) are loaded as Nix expressions.
+    The expressions are combined into a single set, each expression
+    under an attribute with the same name as the original file
+    or subdirectory.
+    </para>
+
+    <para>For example, if <filename>~/.nix-defexpr</filename> contains
+    two files, <filename>foo.nix</filename> and <filename>bar.nix</filename>,
     then the default Nix expression will essentially be
 
 <programlisting>
 {
-  foo = import ~/.nix-defexpr/foo;
-  bar = import ~/.nix-defexpr/bar;
+  foo = import ~/.nix-defexpr/foo.nix;
+  bar = import ~/.nix-defexpr/bar.nix;
 }</programlisting>
 
     </para>
 
+    <para>The file <filename>manifest.nix</filename> is always ignored.
+    Subdirectories without a <filename>default.nix</filename> file
+    are traversed recursively in search of more Nix expressions,
+    but the names of these intermediate directories are not
+    added to the attribute paths of the default Nix expression.</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>
@@ -637,7 +659,7 @@ upgrading `mozilla-1.2' to `mozilla-1.4'</screen>
 <literal>gcc-3.3.1</literal> are split into two parts: the package
 name (<literal>gcc</literal>), and the version
 (<literal>3.3.1</literal>).  The version part starts after the first
-dash not following by a letter.  <varname>x</varname> is considered an
+dash not followed by a letter.  <varname>x</varname> is considered an
 upgrade of <varname>y</varname> if their package names match, and the
 version of <varname>y</varname> is higher that that of
 <varname>x</varname>.</para>
@@ -1044,7 +1066,8 @@ user environment elements, etc. -->
     the derivation, which can be used to unambiguously select it using
     the <link linkend="opt-attr"><option>--attr</option> option</link>
     available in commands that install derivations like
-    <literal>nix-env --install</literal>.</para></listitem>
+    <literal>nix-env --install</literal>. This option only works
+    together with <option>--available</option></para></listitem>
 
   </varlistentry>
 
@@ -1348,10 +1371,13 @@ profile.  The generations can be a list of generation numbers, the
 special value <literal>old</literal> to delete all non-current
 generations,  a value such as <literal>30d</literal> to delete all
 generations older than the specified number of days (except for the
-generation that was active at that point in time), or a value such as.
-<literal>+5</literal> to only keep the specified items older than the
-current generation. Periodically deleting old generations is important
-to make garbage collection effective.</para>
+generation that was active at that point in time), or a value such as
+<literal>+5</literal> to keep the last <literal>5</literal> generations
+ignoring any newer than current, e.g., if <literal>30</literal> is the current
+generation <literal>+5</literal> will delete generation <literal>25</literal>
+and all older generations.
+Periodically deleting old generations is important to make garbage collection
+effective.</para>
 
 </refsection>
 

doc/manual/command-ref/nix-prefetch-url.xml

@@ -53,7 +53,7 @@ avoided.</para>
 <para>If <replaceable>hash</replaceable> is specified, then a download
 is not performed if the Nix store already contains a file with the
 same hash and base name.  Otherwise, the file is downloaded, and an
-error if signaled if the actual hash of the file does not match the
+error is signaled if the actual hash of the file does not match the
 specified hash.</para>
 
 <para>This command prints the hash on standard output.  Additionally,

doc/manual/command-ref/nix-shell.xml

@@ -39,7 +39,12 @@
           <arg choice='plain'><option>--packages</option></arg>
           <arg choice='plain'><option>-p</option></arg>
         </group>
-        <arg choice='plain' rep='repeat'><replaceable>packages</replaceable></arg>
+        <arg choice='plain' rep='repeat'>
+          <group choice='req'>
+            <arg choice="plain"><replaceable>packages</replaceable></arg>
+            <arg choice="plain"><replaceable>expressions</replaceable></arg>
+          </group>
+        </arg>
       </arg>
       <arg><replaceable>path</replaceable></arg>
     </group>
@@ -189,8 +194,8 @@ also <xref linkend="sec-common-options" />.</phrase></para>
 <variablelist>
 
   <varlistentry><term><envar>NIX_BUILD_SHELL</envar></term>
-    
-    <listitem><para>Shell used to start the interactive environment. 
+
+    <listitem><para>Shell used to start the interactive environment.
     Defaults to the <command>bash</command> found in <envar>PATH</envar>.</para></listitem>
 
   </varlistentry>
@@ -222,8 +227,9 @@ $ nix-shell '&lt;nixpkgs>' -A pan --pure \
     --command 'export NIX_DEBUG=1; export NIX_CORES=8; return'
 </screen>
 
-Nix expressions can also be given on the command line.  For instance,
-the following starts a shell containing the packages
+Nix expressions can also be given on the command line using the
+<command>-E</command> and <command>-p</command> flags.
+For instance, the following starts a shell containing the packages
 <literal>sqlite</literal> and <literal>libX11</literal>:
 
 <screen>
@@ -238,6 +244,14 @@ $ nix-shell -p sqlite xorg.libX11
 … -L/nix/store/j1zg5v…-sqlite-3.8.0.2/lib -L/nix/store/0gmcz9…-libX11-1.6.1/lib …
 </screen>
 
+Note that <command>-p</command> accepts multiple full nix expressions that
+are valid in the <literal>buildInputs = [ ... ]</literal> shown above,
+not only package names. So the following is also legal:
+
+<screen>
+$ nix-shell -p sqlite 'git.override { withManual = false; }'
+</screen>
+
 The <command>-p</command> flag looks up Nixpkgs in the Nix search
 path. You can override it by passing <option>-I</option> or setting
 <envar>NIX_PATH</envar>. For example, the following gives you a shell

doc/manual/command-ref/nix-store.xml

@@ -215,6 +215,48 @@ printed.)</para>
 
 </variablelist>
 
+<para>Special exit codes:</para>
+
+<variablelist>
+
+  <varlistentry><term><literal>100</literal></term>
+    <listitem><para>Generic build failure, the builder process
+    returned with a non-zero exit code.</para></listitem>
+  </varlistentry>
+
+  <varlistentry><term><literal>101</literal></term>
+    <listitem><para>Build timeout, the build was aborted because it
+    did not complete within the specified <link
+    linkend='conf-timeout'><literal>timeout</literal></link>.
+    </para></listitem>
+  </varlistentry>
+
+  <varlistentry><term><literal>102</literal></term>
+    <listitem><para>Hash mismatch, the build output was rejected
+    because it does not match the specified <link
+    linkend="fixed-output-drvs"><varname>outputHash</varname></link>.
+    </para></listitem>
+  </varlistentry>
+
+  <varlistentry><term><literal>104</literal></term>
+    <listitem><para>Not deterministic, the build succeeded in check
+    mode but the resulting output is not binary reproducable.</para>
+    </listitem>
+  </varlistentry>
+
+</variablelist>
+
+<para>With the <option>--keep-going</option> flag it's possible for
+multiple failures to occur, in this case the 1xx status codes are or combined
+using binary or. <screen>
+1100100
+   ^^^^
+   |||`- timeout
+   ||`-- output hash mismatch
+   |`--- build failure
+   `---- not deterministic
+</screen></para>
+
 </refsection>
 
 
@@ -318,7 +360,6 @@ EOF
     <arg choice='plain'><option>--print-roots</option></arg>
     <arg choice='plain'><option>--print-live</option></arg>
     <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>
 </cmdsynopsis>
@@ -365,14 +406,6 @@ the Nix store not reachable via file system references from a set of
 
   </varlistentry>
 
-  <varlistentry><term><option>--delete</option></term>
-
-    <listitem><para>This operation performs an actual garbage
-    collection.  All dead paths are removed from the
-    store.  This is the default.</para></listitem>
-
-  </varlistentry>
-
 </variablelist>
 
 <para>By default, all unreachable paths are deleted.  The following
@@ -402,10 +435,10 @@ and <link
 linkend="conf-keep-derivations"><literal>keep-derivations</literal></link>
 variables in the Nix configuration file.</para>
 
-<para>With <option>--delete</option>, the collector prints the total
-number of freed bytes when it finishes (or when it is interrupted).
-With <option>--print-dead</option>, it prints the number of bytes that
-would be freed.</para>
+<para>By default, the collector prints the total number of freed bytes
+when it finishes (or when it is interrupted). With
+<option>--print-dead</option>, it prints the number of bytes that would
+be freed.</para>
 
 </refsection>
 
@@ -883,6 +916,60 @@ $ nix-store --add ./foo.c
 
 </refsection>
 
+<!--######################################################################-->
+
+<refsection><title>Operation <option>--add-fixed</option></title>
+
+<refsection><title>Synopsis</title>
+
+<cmdsynopsis>
+  <command>nix-store</command>
+  <arg><option>--recursive</option></arg>
+  <arg choice='plain'><option>--add-fixed</option></arg>
+  <arg choice='plain'><replaceable>algorithm</replaceable></arg>
+  <arg choice='plain' rep='repeat'><replaceable>paths</replaceable></arg>
+</cmdsynopsis>
+
+</refsection>
+
+<refsection><title>Description</title>
+
+<para>The operation <option>--add-fixed</option> adds the specified paths to
+the Nix store.  Unlike <option>--add</option> paths are registered using the
+specified hashing algorithm, resulting in the same output path as a fixed output
+derivation.  This can be used for sources that are not available from a public
+url or broke since the download expression was written.
+</para>
+
+<para>This operation has the following options:
+
+<variablelist>
+
+  <varlistentry><term><option>--recursive</option></term>
+
+    <listitem><para>
+      Use recursive instead of flat hashing mode, used when adding directories
+      to the store.
+    </para></listitem>
+
+  </varlistentry>
+
+</variablelist>
+
+</para>
+
+</refsection>
+
+<refsection><title>Example</title>
+
+<screen>
+$ nix-store --add-fixed sha256 ./hello-2.10.tar.gz
+/nix/store/3x7dwzq014bblazs7kq20p9hyzz0qh8g-hello-2.10.tar.gz</screen>
+
+</refsection>
+
+</refsection>
+
 
 
 <!--######################################################################-->
@@ -1052,7 +1139,7 @@ the information that Nix considers important.  For instance,
 timestamps are elided because all files in the Nix store have their
 timestamp set to 0 anyway.  Likewise, all permissions are left out
 except for the execute bit, because all files in the Nix store have
-644 or 755 permission.</para>
+444 or 555 permission.</para>
 
 <para>Also, a NAR archive is <emphasis>canonical</emphasis>, meaning
 that “equal” paths always produce the same NAR archive.  For instance,

doc/manual/command-ref/opt-common.xml

@@ -107,14 +107,22 @@
 <varlistentry xml:id="opt-max-jobs"><term><option>--max-jobs</option> / <option>-j</option>
 <replaceable>number</replaceable></term>
 
-  <listitem><para>Sets the maximum number of build jobs that Nix will
+  <listitem>
+
+  <para>Sets the maximum number of build jobs that Nix will
   perform in parallel to the specified number.  Specify
   <literal>auto</literal> to use the number of CPUs in the system.
   The default is specified by the <link
   linkend='conf-max-jobs'><literal>max-jobs</literal></link>
   configuration setting, which itself defaults to
   <literal>1</literal>.  A higher value is useful on SMP systems or to
-  exploit I/O latency.</para></listitem>
+  exploit I/O latency.</para>
+
+  <para> Setting it to <literal>0</literal> disallows building on the local
+  machine, which is useful when you want builds to happen only on remote
+  builders.</para>
+
+  </listitem>
 
 </varlistentry>
 
@@ -235,9 +243,10 @@
 <varlistentry><term><option>--arg</option> <replaceable>name</replaceable> <replaceable>value</replaceable></term>
 
   <listitem><para>This option is accepted by
-  <command>nix-env</command>, <command>nix-instantiate</command> and
-  <command>nix-build</command>.  When evaluating Nix expressions, the
-  expression evaluator will automatically try to call functions that
+  <command>nix-env</command>, <command>nix-instantiate</command>,
+  <command>nix-shell</command> and <command>nix-build</command>.
+  When evaluating Nix expressions, the expression evaluator will
+  automatically try to call functions that
   it encounters.  It can automatically call functions for which every
   argument has a <link linkend='ss-functions'>default value</link>
   (e.g., <literal>{ <replaceable>argName</replaceable> ?
@@ -314,7 +323,14 @@
   Nix expressions to be parsed and evaluated, rather than as a list
   of file names of Nix expressions.
   (<command>nix-instantiate</command>, <command>nix-build</command>
-  and <command>nix-shell</command> only.)</para></listitem>
+  and <command>nix-shell</command> only.)</para>
+
+  <para>For <command>nix-shell</command>, this option is commonly used
+  to give you a shell in which you can build the packages returned
+  by the expression. If you want to get a shell which contain the
+  <emphasis>built</emphasis> packages ready for use, give your
+  expression to the <command>nix-shell -p</command> convenience flag
+  instead.</para></listitem>
 
 </varlistentry>
 

doc/manual/expressions/advanced-attributes.xml

@@ -11,7 +11,7 @@ attributes.</para>
 
 <variablelist>
 
-  <varlistentry><term><varname>allowedReferences</varname></term>
+  <varlistentry xml:id="adv-attr-allowedReferences"><term><varname>allowedReferences</varname></term>
 
     <listitem><para>The optional attribute
     <varname>allowedReferences</varname> specifies a list of legal
@@ -32,7 +32,7 @@ allowedReferences = [];
   </varlistentry>
 
 
-  <varlistentry><term><varname>allowedRequisites</varname></term>
+  <varlistentry xml:id="adv-attr-allowedRequisites"><term><varname>allowedRequisites</varname></term>
 
     <listitem><para>This attribute is similar to
     <varname>allowedReferences</varname>, but it specifies the legal
@@ -50,7 +50,7 @@ allowedRequisites = [ foobar ];
 
   </varlistentry>
 
-  <varlistentry><term><varname>disallowedReferences</varname></term>
+  <varlistentry xml:id="adv-attr-disallowedReferences"><term><varname>disallowedReferences</varname></term>
 
     <listitem><para>The optional attribute
     <varname>disallowedReferences</varname> specifies a list of illegal
@@ -67,7 +67,7 @@ disallowedReferences = [ foo ];
   </varlistentry>
 
 
-  <varlistentry><term><varname>disallowedRequisites</varname></term>
+  <varlistentry xml:id="adv-attr-disallowedRequisites"><term><varname>disallowedRequisites</varname></term>
 
     <listitem><para>This attribute is similar to
     <varname>disallowedReferences</varname>, but it specifies illegal
@@ -85,7 +85,7 @@ disallowedRequisites = [ foobar ];
   </varlistentry>
 
 
-  <varlistentry><term><varname>exportReferencesGraph</varname></term>
+  <varlistentry xml:id="adv-attr-exportReferencesGraph"><term><varname>exportReferencesGraph</varname></term>
 
     <listitem><para>This attribute allows builders access to the
     references graph of their inputs.  The attribute is a list of
@@ -124,7 +124,7 @@ derivation {
   </varlistentry>
 
 
-  <varlistentry><term><varname>impureEnvVars</varname></term>
+  <varlistentry xml:id="adv-attr-impureEnvVars"><term><varname>impureEnvVars</varname></term>
 
     <listitem><para>This attribute allows you to specify a list of
     environment variables that should be passed from the environment
@@ -158,9 +158,9 @@ impureEnvVars = [ "http_proxy" "https_proxy" <replaceable>...</replaceable> ];
 
 
   <varlistentry xml:id="fixed-output-drvs">
-    <term><varname>outputHash</varname></term>
-    <term><varname>outputHashAlgo</varname></term>
-    <term><varname>outputHashMode</varname></term>
+    <term xml:id="adv-attr-outputHash"><varname>outputHash</varname></term>
+    <term xml:id="adv-attr-outputHashAlgo"><varname>outputHashAlgo</varname></term>
+    <term xml:id="adv-attr-outputHashMode"><varname>outputHashMode</varname></term>
 
     <listitem><para>These attributes declare that the derivation is a
     so-called <emphasis>fixed-output derivation</emphasis>, which
@@ -282,7 +282,7 @@ stdenv.mkDerivation {
   </varlistentry>
 
 
-  <varlistentry><term><varname>passAsFile</varname></term>
+  <varlistentry xml:id="adv-attr-passAsFile"><term><varname>passAsFile</varname></term>
 
     <listitem><para>A list of names of attributes that should be
     passed via files rather than environment variables.  For example,
@@ -309,7 +309,7 @@ big = "a very long string";
   </varlistentry>
 
 
-  <varlistentry><term><varname>preferLocalBuild</varname></term>
+  <varlistentry xml:id="adv-attr-preferLocalBuild"><term><varname>preferLocalBuild</varname></term>
 
     <listitem><para>If this attribute is set to
     <literal>true</literal> and <link
@@ -323,14 +323,25 @@ big = "a very long string";
   </varlistentry>
 
 
-  <varlistentry><term><varname>allowSubstitutes</varname></term>
+  <varlistentry xml:id="adv-attr-allowSubstitutes"><term><varname>allowSubstitutes</varname></term>
 
-    <listitem><para>If this attribute is set to
+    <listitem>
+    <para>If this attribute is set to
     <literal>false</literal>, then Nix will always build this
     derivation; it will not try to substitute its outputs. This is
     useful for very trivial derivations (such as
     <function>writeText</function> in Nixpkgs) that are cheaper to
-    build than to substitute from a binary cache.</para></listitem>
+    build than to substitute from a binary cache.</para>
+
+    <note><para>You need to have a builder configured which satisfies
+    the derivation’s <literal>system</literal> attribute, since the
+    derivation cannot be substituted. Thus it is usually a good idea
+    to align <literal>system</literal> with
+    <literal>builtins.currentSystem</literal> when setting
+    <literal>allowSubstitutes</literal> to <literal>false</literal>.
+    For most trivial derivations this should be the case.
+    </para></note>
+    </listitem>
 
   </varlistentry>
 

doc/manual/expressions/builtins.xml

@@ -170,18 +170,6 @@ if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting>
   </varlistentry>
 
 
-  <varlistentry xml:id='builtin-splitVersion'>
-    <term><function>builtins.splitVersion</function>
-    <replaceable>s</replaceable></term>
-
-    <listitem><para>Split a string representing a version into its
-    components, by the same version splitting logic underlying the
-    version comparison in <link linkend="ssec-version-comparisons">
-    <command>nix-env -u</command></link>.</para></listitem>
-
-  </varlistentry>
-
-
   <varlistentry xml:id='builtin-concatLists'>
     <term><function>builtins.concatLists</function>
     <replaceable>lists</replaceable></term>
@@ -301,7 +289,7 @@ if builtins ? getEnv then builtins.getEnv "PATH" else ""</programlisting>
 
     <listitem><para>Return element <replaceable>n</replaceable> from
     the list <replaceable>xs</replaceable>.  Elements are counted
-    starting from 0.  A fatal error occurs in the index is out of
+    starting from 0.  A fatal error occurs if the index is out of
     bounds.</para></listitem>
 
   </varlistentry>
@@ -347,7 +335,7 @@ stdenv.mkDerivation { … }
     You can change the cache timeout either on the command line with
     <option>--option tarball-ttl <replaceable>number of seconds</replaceable></option> or
     in the Nix configuration file with this option:
-    <literal>tarball-ttl <replaceable>number of seconds to cache</replaceable></literal>.
+    <literal><xref linkend="conf-tarball-ttl" /> <replaceable>number of seconds to cache</replaceable></literal>.
     </para>
 
     <para>Note that when obtaining the hash with <varname>nix-prefetch-url
@@ -425,6 +413,13 @@ stdenv.mkDerivation { … }
               This is often a branch or tag name. Defaults to
               <literal>HEAD</literal>.
             </para>
+
+            <para>
+              By default, the <varname>ref</varname> value is prefixed
+              with <literal>refs/heads/</literal>. As of Nix 2.3.0
+              Nix will not prefix <literal>refs/heads/</literal> if
+              <varname>ref</varname> starts with <literal>refs/</literal>.
+            </para>
           </listitem>
         </varlistentry>
       </variablelist>
@@ -438,6 +433,14 @@ stdenv.mkDerivation { … }
 }</programlisting>
       </example>
 
+      <example>
+        <title>Fetching an arbitrary ref</title>
+        <programlisting>builtins.fetchGit {
+  url = "https://github.com/NixOS/nix.git";
+  ref = "refs/heads/0.5-release";
+}</programlisting>
+      </example>
+
       <example>
         <title>Fetching a repository's specific commit on an arbitrary branch</title>
         <para>
@@ -484,11 +487,8 @@ stdenv.mkDerivation { … }
         <title>Fetching a tag</title>
         <programlisting>builtins.fetchGit {
   url = "https://github.com/nixos/nix.git";
-  ref = "tags/1.9";
+  ref = "refs/tags/1.9";
 }</programlisting>
-        <note><para>Due to a bug (<link
-        xlink:href="https://github.com/NixOS/nix/issues/2385">#2385</link>),
-        only non-annotated tags can be fetched.</para></note>
       </example>
 
       <example>
@@ -498,7 +498,7 @@ stdenv.mkDerivation { … }
            fetch the latest version of a remote branch.
         </para>
         <note><para>Nix will refetch the branch in accordance to
-        <option>tarball-ttl</option>.</para></note>
+        <xref linkend="conf-tarball-ttl" />.</para></note>
         <note><para>This behavior is disabled in
         <emphasis>Pure evaluation mode</emphasis>.</para></note>
         <programlisting>builtins.fetchGit {
@@ -705,6 +705,19 @@ builtins.genList (x: x * x) 5
   </varlistentry>
 
 
+  <varlistentry xml:id='builtin-hashFile'>
+    <term><function>builtins.hashFile</function>
+    <replaceable>type</replaceable> <replaceable>p</replaceable></term>
+
+    <listitem><para>Return a base-16 representation of the
+    cryptographic hash of the file at path <replaceable>p</replaceable>.  The
+    hash algorithm specified by <replaceable>type</replaceable> must
+    be one of <literal>"md5"</literal>, <literal>"sha1"</literal>,
+    <literal>"sha256"</literal> or <literal>"sha512"</literal>.</para></listitem>
+
+  </varlistentry>
+
+
   <varlistentry xml:id='builtin-head'>
     <term><function>builtins.head</function>
     <replaceable>list</replaceable></term>
@@ -733,6 +746,11 @@ builtins.genList (x: x * x) 5
     separate file, and use it from Nix expressions in other
     files.</para>
 
+    <note><para>Unlike some languages, <function>import</function> is a regular
+    function in Nix. Paths using the angle bracket syntax (e.g., <function>
+    import</function> <replaceable>&lt;foo&gt;</replaceable>) are normal path
+    values (see <xref linkend='ssec-values' />).</para></note>
+
     <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
@@ -1102,6 +1120,16 @@ Evaluates to <literal>[ "foo" ]</literal>.
 
   </varlistentry>
 
+  <varlistentry xml:id='builtin-placeholder'>
+    <term><function>builtins.placeholder</function>
+    <replaceable>output</replaceable></term>
+
+    <listitem><para>Return a placeholder string for the specified
+    <replaceable>output</replaceable> that will be substituted by the
+    corresponding output path at build time. Typical outputs would be
+    <literal>"out"</literal>, <literal>"bin"</literal> or
+    <literal>"dev"</literal>.</para></listitem>
+  </varlistentry>
 
   <varlistentry xml:id='builtin-readDir'>
     <term><function>builtins.readDir</function>
@@ -1247,6 +1275,19 @@ Evaluates to <literal>[ "  " [ "FOO" ] "   " ]</literal>.
     </para></listitem>
   </varlistentry>
 
+
+  <varlistentry xml:id='builtin-splitVersion'>
+    <term><function>builtins.splitVersion</function>
+    <replaceable>s</replaceable></term>
+
+    <listitem><para>Split a string representing a version into its
+    components, by the same version splitting logic underlying the
+    version comparison in <link linkend="ssec-version-comparisons">
+    <command>nix-env -u</command></link>.</para></listitem>
+
+  </varlistentry>
+
+
   <varlistentry xml:id='builtin-stringLength'>
     <term><function>builtins.stringLength</function>
     <replaceable>e</replaceable></term>
@@ -1440,7 +1481,7 @@ in foo</programlisting>
       <listitem><para>A set containing <literal>{ __toString = self: ...; }</literal>.</para></listitem>
       <listitem><para>An integer.</para></listitem>
       <listitem><para>A list, in which case the string representations of its elements are joined with spaces.</para></listitem>
-      <listitem><para>A Boolean (<literal>false</literal> yields <literal>""</literal>, <literal>true</literal> yields <literal>"1"</literal>.</para></listitem>
+      <listitem><para>A Boolean (<literal>false</literal> yields <literal>""</literal>, <literal>true</literal> yields <literal>"1"</literal>).</para></listitem>
       <listitem><para><literal>null</literal>, which yields the empty string.</para></listitem>
     </itemizedlist>
     </listitem>
@@ -1579,12 +1620,18 @@ stdenv.mkDerivation (rec {
     <term><function>builtins.tryEval</function>
     <replaceable>e</replaceable></term>
 
-    <listitem><para>Try to evaluate <replaceable>e</replaceable>.
+    <listitem><para>Try to shallowly evaluate <replaceable>e</replaceable>.
     Return a set containing the attributes <literal>success</literal>
     (<literal>true</literal> if <replaceable>e</replaceable> evaluated
     successfully, <literal>false</literal> if an error was thrown) and
     <literal>value</literal>, equalling <replaceable>e</replaceable>
-    if successful and <literal>false</literal> otherwise.
+    if successful and <literal>false</literal> otherwise. Note that this
+    doesn't evaluate <replaceable>e</replaceable> deeply, so
+    <literal>let e = { x = throw ""; }; in (builtins.tryEval e).success
+    </literal> will be <literal>true</literal>. Using <literal>builtins.deepSeq
+    </literal> one can get the expected result: <literal>let e = { x = throw "";
+    }; in (builtins.tryEval (builtins.deepSeq e e)).success</literal> will be
+    <literal>false</literal>.
     </para></listitem>
 
   </varlistentry>

doc/manual/expressions/language-constructs.xml

@@ -43,7 +43,7 @@ encountered</quote>).</para></footnote>.</para>
 
 <simplesect xml:id="sect-let-expressions"><title>Let-expressions</title>
 
-<para>A let-expression allows you define local variables for an
+<para>A let-expression allows you to define local variables for an
 expression.  For instance,
 
 <programlisting>
@@ -217,7 +217,25 @@ but can also be written as:
   ellipsis(<literal>...</literal>) as you can access attribute names as 
   <literal>a</literal>, using <literal>args.a</literal>, which was given as an
   additional attribute to the function.
-  </para></listitem>
+  </para>
+
+  <warning>
+   <para>
+    The <literal>args@</literal> expression is bound to the argument passed to the function which
+    means that attributes with defaults that aren't explicitly specified in the function call
+    won't cause an evaluation error, but won't exist in <literal>args</literal>.
+   </para>
+   <para>
+    For instance
+<programlisting>
+let
+  function = args@{ a ? 23, ... }: args;
+in
+ function {}
+</programlisting>
+    will evaluate to an empty attribute set.
+   </para>
+  </warning></listitem>
 
 </itemizedlist>
 

doc/manual/expressions/language-operators.xml

@@ -15,13 +15,16 @@ weakest binding).</para>
   <tgroup cols='3'>
     <thead>
       <row>
+        <entry>Name</entry>
         <entry>Syntax</entry>
         <entry>Associativity</entry>
         <entry>Description</entry>
+        <entry>Precedence</entry>
       </row>
     </thead>
     <tbody>
       <row>
+        <entry>Select</entry>
         <entry><replaceable>e</replaceable> <literal>.</literal>
         <replaceable>attrpath</replaceable>
         [ <literal>or</literal> <replaceable>def</replaceable> ]
@@ -33,19 +36,25 @@ weakest binding).</para>
         dot-separated list of attribute names.)  If the attribute
         doesn’t exist, return <replaceable>def</replaceable> if
         provided, otherwise abort evaluation.</entry>
+        <entry>1</entry>
       </row>
       <row>
+        <entry>Application</entry>
         <entry><replaceable>e1</replaceable> <replaceable>e2</replaceable></entry>
         <entry>left</entry>
         <entry>Call function <replaceable>e1</replaceable> with
         argument <replaceable>e2</replaceable>.</entry>
+        <entry>2</entry>
       </row>
       <row>
+        <entry>Arithmetic Negation</entry>
         <entry><literal>-</literal> <replaceable>e</replaceable></entry>
         <entry>none</entry>
         <entry>Arithmetic negation.</entry>
+        <entry>3</entry>
       </row>
       <row>
+        <entry>Has Attribute</entry>
         <entry><replaceable>e</replaceable> <literal>?</literal>
         <replaceable>attrpath</replaceable></entry>
         <entry>none</entry>
@@ -53,34 +62,69 @@ weakest binding).</para>
         the attribute denoted by <replaceable>attrpath</replaceable>;
         return <literal>true</literal> or
         <literal>false</literal>.</entry>
+        <entry>4</entry>
       </row>
       <row>
+        <entry>List Concatenation</entry>
         <entry><replaceable>e1</replaceable> <literal>++</literal> <replaceable>e2</replaceable></entry>
         <entry>right</entry>
         <entry>List concatenation.</entry>
+        <entry>5</entry>
       </row>
       <row>
+        <entry>Multiplication</entry>
         <entry>
           <replaceable>e1</replaceable> <literal>*</literal> <replaceable>e2</replaceable>,
+        </entry>
+        <entry>left</entry>
+        <entry>Arithmetic multiplication.</entry>
+        <entry>6</entry>
+      </row>
+      <row>
+        <entry>Division</entry>
+        <entry>
           <replaceable>e1</replaceable> <literal>/</literal> <replaceable>e2</replaceable>
         </entry>
         <entry>left</entry>
-        <entry>Arithmetic multiplication and division.</entry>
+        <entry>Arithmetic division.</entry>
+        <entry>6</entry>
       </row>
       <row>
+        <entry>Addition</entry>
+        <entry>
+          <replaceable>e1</replaceable> <literal>+</literal> <replaceable>e2</replaceable>
+        </entry>
+        <entry>left</entry>
+        <entry>Arithmetic addition.</entry>
+        <entry>7</entry>
+      </row>
+      <row>
+        <entry>Subtraction</entry>
         <entry>
-          <replaceable>e1</replaceable> <literal>+</literal> <replaceable>e2</replaceable>,
           <replaceable>e1</replaceable> <literal>-</literal> <replaceable>e2</replaceable>
         </entry>
         <entry>left</entry>
-        <entry>Arithmetic addition and subtraction.  String or path concatenation (only by <literal>+</literal>).</entry>
+        <entry>Arithmetic subtraction.</entry>
+        <entry>7</entry>
       </row>
       <row>
+        <entry>String Concatenation</entry>
+        <entry>
+          <replaceable>string1</replaceable> <literal>+</literal> <replaceable>string2</replaceable>
+        </entry>
+        <entry>left</entry>
+        <entry>String concatenation.</entry>
+        <entry>7</entry>
+      </row>
+      <row>
+        <entry>Not</entry>
         <entry><literal>!</literal> <replaceable>e</replaceable></entry>
         <entry>none</entry>
         <entry>Boolean negation.</entry>
+        <entry>8</entry>
       </row>
       <row>
+        <entry>Update</entry>
         <entry><replaceable>e1</replaceable> <literal>//</literal>
         <replaceable>e2</replaceable></entry>
         <entry>right</entry>
@@ -89,47 +133,90 @@ weakest binding).</para>
         <replaceable>e2</replaceable> (with the latter taking
         precedence over the former in case of equally named
         attributes).</entry>
+        <entry>9</entry>
       </row>
       <row>
+        <entry>Less Than</entry>
         <entry>
           <replaceable>e1</replaceable> <literal>&lt;</literal> <replaceable>e2</replaceable>,
-          <replaceable>e1</replaceable> <literal>&gt;</literal> <replaceable>e2</replaceable>,
-          <replaceable>e1</replaceable> <literal>&lt;=</literal> <replaceable>e2</replaceable>,
+        </entry>
+        <entry>none</entry>
+        <entry>Arithmetic comparison.</entry>
+        <entry>10</entry>
+      </row>
+      <row>
+        <entry>Less Than or Equal To</entry>
+        <entry>
+          <replaceable>e1</replaceable> <literal>&lt;=</literal> <replaceable>e2</replaceable>
+        </entry>
+        <entry>none</entry>
+        <entry>Arithmetic comparison.</entry>
+        <entry>10</entry>
+      </row>
+      <row>
+        <entry>Greater Than</entry>
+        <entry>
+          <replaceable>e1</replaceable> <literal>&gt;</literal> <replaceable>e2</replaceable>
+        </entry>
+        <entry>none</entry>
+        <entry>Arithmetic comparison.</entry>
+        <entry>10</entry>
+      </row>
+      <row>
+        <entry>Greater Than or Equal To</entry>
+        <entry>
           <replaceable>e1</replaceable> <literal>&gt;=</literal> <replaceable>e2</replaceable>
         </entry>
         <entry>none</entry>
         <entry>Arithmetic comparison.</entry>
+        <entry>10</entry>
       </row>
       <row>
+        <entry>Equality</entry>
+        <entry>
+          <replaceable>e1</replaceable> <literal>==</literal> <replaceable>e2</replaceable>
+        </entry>
+        <entry>none</entry>
+        <entry>Equality.</entry>
+        <entry>11</entry>
+      </row>
+      <row>
+        <entry>Inequality</entry>
         <entry>
-          <replaceable>e1</replaceable> <literal>==</literal> <replaceable>e2</replaceable>,
           <replaceable>e1</replaceable> <literal>!=</literal> <replaceable>e2</replaceable>
         </entry>
         <entry>none</entry>
-        <entry>Equality and inequality.</entry>
+        <entry>Inequality.</entry>
+        <entry>11</entry>
       </row>
       <row>
+        <entry>Logical AND</entry>
         <entry><replaceable>e1</replaceable> <literal>&amp;&amp;</literal>
         <replaceable>e2</replaceable></entry>
         <entry>left</entry>
         <entry>Logical AND.</entry>
+        <entry>12</entry>
       </row>
       <row>
+        <entry>Logical OR</entry>
         <entry><replaceable>e1</replaceable> <literal>||</literal>
         <replaceable>e2</replaceable></entry>
         <entry>left</entry>
         <entry>Logical OR.</entry>
+        <entry>13</entry>
       </row>
       <row>
+        <entry>Logical Implication</entry>
         <entry><replaceable>e1</replaceable> <literal>-></literal>
         <replaceable>e2</replaceable></entry>
         <entry>none</entry>
         <entry>Logical implication (equivalent to
         <literal>!<replaceable>e1</replaceable> ||
         <replaceable>e2</replaceable></literal>).</entry>
+        <entry>14</entry>
       </row>
     </tbody>
   </tgroup>
 </table>
 
-</section>
+</section>

doc/manual/expressions/simple-building-testing.xml

@@ -43,7 +43,7 @@ use <command>nix-build</command>’s <option
 linkend='opt-out-link'>-o</option> switch to give the symlink another
 name.</para>
 
-<para>Nix has a transactional semantics.  Once a build finishes
+<para>Nix has transactional semantics.  Once a build finishes
 successfully, Nix makes a note of this in its database: it registers
 that the path denoted by <envar>out</envar> is now
 <quote>valid</quote>.  If you try to build the derivation again, Nix

doc/manual/installation/env-variables.xml

@@ -67,5 +67,23 @@ $ sudo launchctl kickstart -k system/org.nixos.nix-daemon
 </screen>
 </section>
 
+<section xml:id="sec-installer-proxy-settings">
+
+<title>Proxy Environment Variables</title>
+
+<para>The Nix installer has special handling for these proxy-related
+environment variables:
+<varname>http_proxy</varname>, <varname>https_proxy</varname>,
+<varname>ftp_proxy</varname>, <varname>no_proxy</varname>,
+<varname>HTTP_PROXY</varname>, <varname>HTTPS_PROXY</varname>,
+<varname>FTP_PROXY</varname>, <varname>NO_PROXY</varname>.
+</para>
+<para>If any of these variables are set when running the Nix installer,
+then the installer will create an override file at
+<filename>/etc/systemd/system/nix-daemon.service.d/override.conf</filename>
+so <command>nix-daemon</command> will use them.
+</para>
+</section>
+
 </section>
 </chapter>

doc/manual/installation/installing-binary.xml

@@ -142,7 +142,7 @@ sudo rm /Library/LaunchDaemons/org.nixos.nix-daemon.plist
   <para>
     NixOS.org hosts version-specific installation URLs for all Nix
     versions since 1.11.16, at
-    <literal>https://nixos.org/releases/nix/nix-VERSION/install</literal>.
+    <literal>https://releases.nixos.org/nix/nix-<replaceable>version</replaceable>/install</literal>.
   </para>
 
   <para>

doc/manual/installation/prerequisites-source.xml

@@ -8,12 +8,20 @@
 
 <itemizedlist>
 
+  <listitem><para>GNU Autoconf
+  (<link xlink:href="https://www.gnu.org/software/autoconf/"/>)
+  and the autoconf-archive macro collection
+  (<link xlink:href="https://www.gnu.org/software/autoconf-archive/"/>).
+  These are only needed to run the bootstrap script, and are not necessary
+  if your source distribution came with a pre-built
+  <literal>./configure</literal> script.</para></listitem>
+
   <listitem><para>GNU Make.</para></listitem>
   
   <listitem><para>Bash Shell. The <literal>./configure</literal> script
   relies on bashisms, so Bash is required.</para></listitem>
 
-  <listitem><para>A version of GCC or Clang that supports C++14.</para></listitem>
+  <listitem><para>A version of GCC or Clang that supports C++17.</para></listitem>
 
   <listitem><para><command>pkg-config</command> to locate
   dependencies.  If your distribution does not provide it, you can get
@@ -62,6 +70,10 @@
   1.66.0 or higher. It can be obtained from the official web site
   <link xlink:href="https://www.boost.org/" />.</para></listitem>
 
+  <listitem><para>The <literal>editline</literal> library of version
+  1.14.0 or higher. It can be obtained from the its repository
+  <link xlink:href="https://github.com/troglobit/editline" />.</para></listitem>
+
   <listitem><para>The <command>xmllint</command> and
   <command>xsltproc</command> programs to build this manual and the
   man-pages.  These are part of the <literal>libxml2</literal> and

doc/manual/local.mk

@@ -4,11 +4,10 @@ ifeq ($(doc_generate),yes)
 XSLTPROC = $(xsltproc) --nonet $(xmlflags) \
   --param section.autolabel 1 \
   --param section.label.includes.component.label 1 \
-  --param html.stylesheet \'style.css\' \
   --param xref.with.number.and.title 1 \
   --param toc.section.depth 3 \
   --param admon.style \'\' \
-  --param callout.graphics.extension \'.gif\' \
+  --param callout.graphics 0 \
   --param contrib.inline.enabled 0 \
   --stringparam generate.toc "book toc" \
   --param keep.relative.image.uris 0
@@ -66,12 +65,10 @@ $(d)/manual.html: $(d)/manual.xml $(MANUAL_SRCS) $(d)/manual.is-valid
 	  $(docbookxsl)/profiling/profile.xsl $< | \
 	  $(XSLTPROC) --output $@ $(docbookxsl)/xhtml/docbook.xsl -
 
-$(foreach file, $(d)/manual.html $(d)/style.css, $(eval $(call install-data-in, $(file), $(docdir)/manual)))
+$(foreach file, $(d)/manual.html, $(eval $(call install-data-in, $(file), $(docdir)/manual)))
 
 $(foreach file, $(wildcard $(d)/figures/*.png), $(eval $(call install-data-in, $(file), $(docdir)/manual/figures)))
 
-$(foreach file, $(wildcard $(d)/images/callouts/*.gif), $(eval $(call install-data-in, $(file), $(docdir)/manual/images/callouts)))
-
 $(eval $(call install-symlink, manual.html, $(docdir)/manual/index.html))
 
 

doc/manual/packages/basic-package-mgmt.xml

@@ -24,11 +24,11 @@ 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 packages,
 including, if necessary, their dependencies.  There is a collection of
-Nix expressions called the Nix Package collection that contains
+Nix expressions called the Nixpkgs package collection that contains
 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.)</para>
+tied to the Nixpkgs package collection; you could write your own Nix
+expressions based on Nixpkgs, or completely new ones.)</para>
 
 <para>You can manually download the latest version of Nixpkgs from
 <link xlink:href='http://nixos.org/nixpkgs/download.html'/>. However,

doc/manual/packages/channels.xml

@@ -17,6 +17,9 @@ a set of Nix expressions and a manifest.  Using the command <link
 linkend="sec-nix-channel"><command>nix-channel</command></link> you
 can automatically stay up to date with whatever is available at that
 URL.</para>
+      
+<para>To see the list of official NixOS channels, visit <link
+xlink:href="https://nixos.org/channels" />.</para>
 
 <para>You can “subscribe” to a channel using
 <command>nix-channel --add</command>, e.g.,

doc/manual/packages/garbage-collection.xml

@@ -52,12 +52,13 @@ garbage collector as follows:
 <screen>
 $ nix-store --gc</screen>
 
-The behaviour of the gargage collector is affected by the <literal>keep-
-derivations</literal> (default: true) and <literal>keep-outputs</literal>
+The behaviour of the gargage collector is affected by the 
+<literal>keep-derivations</literal> (default: true) and <literal>keep-outputs</literal>
 (default: false) options in the Nix configuration file. The defaults will ensure
-that all derivations that are not build-time dependencies of garbage collector roots
-will be collected but that all output paths that are not runtime dependencies
-will be collected. (This is usually what you want, but while you are developing
+that all derivations that are build-time dependencies of garbage collector roots
+will be kept and that all output paths that are runtime dependencies
+will be kept as well. All other derivations or paths will be collected. 
+(This is usually what you want, but while you are developing
 it may make sense to keep outputs to ensure that rebuild times are quick.)
 
 If you are feeling uncertain, you can also first view what files would

doc/manual/packages/s3-substituter.xml

@@ -113,7 +113,7 @@ the S3 URL:</para>
   exactly <uri>s3://example-nix-cache</uri>.</para>
 
   <para>Nix will use the <link
-  xlink:href="https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/credentials.html#credentials-default.">default
+  xlink:href="https://docs.aws.amazon.com/sdk-for-cpp/v1/developer-guide/credentials.html">default
   credential provider chain</link> for authenticating requests to
   Amazon S3.</para>
 
@@ -138,7 +138,7 @@ the S3 URL:</para>
   be <uri>s3://example-nix-cache</uri>.</para>
 
   <para>Nix will use the <link
-  xlink:href="https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/credentials.html#credentials-default.">default
+  xlink:href="https://docs.aws.amazon.com/sdk-for-cpp/v1/developer-guide/credentials.html">default
   credential provider chain</link> for authenticating requests to
   Amazon S3.</para>
 
@@ -159,7 +159,6 @@ the S3 URL:</para>
         "s3:ListBucket",
         "s3:ListBucketMultipartUploads",
         "s3:ListMultipartUploadParts",
-        "s3:ListObjects",
         "s3:PutObject"
       ],
       "Resource": [

doc/manual/release-notes/release-notes.xml

@@ -12,6 +12,7 @@
 </partintro>
 -->
 
+<xi:include href="rl-2.3.xml" />
 <xi:include href="rl-2.2.xml" />
 <xi:include href="rl-2.1.xml" />
 <xi:include href="rl-2.0.xml" />

doc/manual/release-notes/rl-2.0.xml

@@ -503,14 +503,14 @@
   </listitem>
 
   <listitem>
-    <para><emphasis>Pure evaluation mode</emphasis>. This is a variant
-    of the existing restricted evaluation mode. In pure mode, the Nix
-    evaluator forbids access to anything that could cause different
-    evaluations of the same command line arguments to produce a
+    <para><emphasis>Pure evaluation mode</emphasis>. With the
+    <literal>--pure-eval</literal> flag, Nix enables a variant of the existing
+    restricted evaluation mode that forbids access to anything that could cause
+    different evaluations of the same command line arguments to produce a
     different result. This includes builtin functions such as
     <function>builtins.getEnv</function>, but more importantly,
-    <emphasis>all</emphasis> filesystem or network access unless a
-    content hash or commit hash is specified. For example, calls to
+    <emphasis>all</emphasis> filesystem or network access unless a content hash
+    or commit hash is specified. For example, calls to
     <function>builtins.fetchGit</function> are only allowed if a
     <varname>rev</varname> attribute is specified.</para>
 

doc/manual/release-notes/rl-2.3.xml

@@ -0,0 +1,91 @@
+<section xmlns="http://docbook.org/ns/docbook"
+      xmlns:xlink="http://www.w3.org/1999/xlink"
+      xmlns:xi="http://www.w3.org/2001/XInclude"
+      version="5.0"
+      xml:id="ssec-relnotes-2.3">
+
+<title>Release 2.3 (2019-09-04)</title>
+
+<para>This is primarily a bug fix release. However, it makes some
+incompatible changes:</para>
+
+<itemizedlist>
+
+  <listitem>
+    <para>Nix now uses BSD file locks instead of POSIX file
+    locks. Because of this, you should not use Nix 2.3 and previous
+    releases at the same time on a Nix store.</para>
+  </listitem>
+
+</itemizedlist>
+
+<para>It also has the following changes:</para>
+
+<itemizedlist>
+
+  <listitem>
+    <para><function>builtins.fetchGit</function>'s <varname>ref</varname>
+    argument now allows specifying an absolute remote ref.
+    Nix will automatically prefix <varname>ref</varname> with
+    <literal>refs/heads</literal> only if <varname>ref</varname> doesn't
+    already begin with <literal>refs/</literal>.
+    </para>
+  </listitem>
+
+  <listitem>
+    <para>The installer now enables sandboxing by default on Linux when the
+    system has the necessary kernel support.
+    </para>
+  </listitem>
+
+  <listitem>
+    <para>The <literal>max-jobs</literal> setting now defaults to 1.</para>
+  </listitem>
+
+  <listitem>
+    <para>New builtin functions:
+    <literal>builtins.isPath</literal>,
+    <literal>builtins.hashFile</literal>.
+    </para>
+  </listitem>
+
+  <listitem>
+    <para>The <command>nix</command> command has a new
+    <option>--print-build-logs</option> (<option>-L</option>) flag to
+    print build log output to stderr, rather than showing the last log
+    line in the progress bar. To distinguish between concurrent
+    builds, log lines are prefixed by the name of the package.
+    </para>
+  </listitem>
+
+  <listitem>
+    <para>Builds are now executed in a pseudo-terminal, and the
+    <envar>TERM</envar> environment variable is set to
+    <literal>xterm-256color</literal>. This allows many programs
+    (e.g. <command>gcc</command>, <command>clang</command>,
+    <command>cmake</command>) to print colorized log output.</para>
+  </listitem>
+
+  <listitem>
+    <para>Add <option>--no-net</option> convenience flag. This flag
+    disables substituters; sets the <literal>tarball-ttl</literal>
+    setting to infinity (ensuring that any previously downloaded files
+    are considered current); and disables retrying downloads and sets
+    the connection timeout to the minimum. This flag is enabled
+    automatically if there are no configured non-loopback network
+    interfaces.</para>
+  </listitem>
+
+  <listitem>
+    <para>Add a <literal>post-build-hook</literal> setting to run a
+    program after a build has succeeded.</para>
+  </listitem>
+
+  <listitem>
+    <para>Add a <literal>trace-function-calls</literal> setting to log
+    the duration of Nix function calls to stderr.</para>
+  </listitem>
+
+</itemizedlist>
+
+</section>

doc/manual/style.css

@@ -1,263 +0,0 @@
-/* Copied from http://bakefile.sourceforge.net/, which appears
-   licensed under the GNU GPL. */
-
-
-/***************************************************************************
-                             Basic headers and text:
- ***************************************************************************/
-
-body
-{
-    font-family: "Nimbus Sans L", sans-serif;
-    background: white;
-    margin: 2em 1em 2em 1em;
-}
-
-h1, h2, h3, h4
-{
-    color: #005aa0;
-}
-
-h1 /* title */
-{
-    font-size: 200%;
-}
-
-div.part h1
-{
-    font-size: 240%;
-}
-
-h2 /* chapters, appendices, subtitle */
-{
-    font-size: 180%;
-}
-
-div.part
-{
-    margin-top: 4em;
-}
-
-/* Extra space between chapters, appendices. */
-div.chapter > div.titlepage h2, div.appendix > div.titlepage h2 
-{ 
-    margin-top: 1.5em;
-}
-
-div.section > div.titlepage h2 /* sections */
-{
-    font-size: 150%;
-    margin-top: 1.5em;
-}
-
-h3 /* subsections */
-{
-    font-size: 125%;
-}
-
-div.simplesect h2
-{
-    font-size: 110%;
-}
-
-div.appendix h3
-{
-    font-size: 150%;
-    margin-top: 1.5em;
-}
-
-div.refentry\.separator
-{
-    margin-top: 2.5em;
-    margin-bottom: 2em;
-}
-
-div.refnamediv h2, div.refsynopsisdiv h2, div.refsection h2 /* refentry parts */
-{
-    margin-top: 1.4em;
-    font-size: 125%;
-}
-
-div.refsection h3
-{
-    font-size: 110%;
-}
-
-
-/***************************************************************************
-                               Examples:
- ***************************************************************************/
-
-div.example
-{
-    border: 1px solid #b0b0b0;
-    padding: 6px 6px;
-    margin-left: 1.5em;
-    margin-right: 1.5em;
-    background: #f4f4f8;
-    border-radius: 0.4em;
-}
-
-div.example p.title
-{
-    margin-top: 0em;
-}
-
-div.example pre
-{
-}
-
-
-/***************************************************************************
-                            Screen dumps:
- ***************************************************************************/
-
-pre.screen, pre.programlisting
-{
-    padding: 6px 6px;
-    margin-left: 1.5em;
-    margin-right: 1.5em;
-    color: #600000;
-    background: #f4f4f8;
-    font-family: monospace;
-}
-
-div.example pre.programlisting
-{
-    border: 0px;
-    padding: 0 0;
-    margin: 0 0 0 0;
-}
-
-
-/***************************************************************************
-                               Notes, warnings etc:
- ***************************************************************************/
-
-.note, .warning
-{
-    border: 1px solid #b0b0b0;
-    padding: 3px 3px;
-    margin-left: 1.5em;
-    margin-right: 1.5em;
-    margin-bottom: 1em;
-    padding: 0.3em 0.3em 0.3em 0.3em;
-    background: #fffff5;
-    border-radius: 0.4em;
-}
-
-div.note, div.warning
-{
-    font-style: italic;
-}
-
-div.note h3, div.warning h3
-{
-    color: red;
-    font-size: 100%;
-    padding-right: 0.5em;
-    display: inline;
-}
-
-div.note p, div.warning p
-{
-    margin-bottom: 0em;
-}
-
-div.note h3 + p, div.warning h3 + p
-{
-    display: inline;
-}
-
-div.note h3
-{
-    color: blue;
-    font-size: 100%;
-}
-
-div.navfooter *
-{
-    font-size: 90%;
-}
-
-
-/***************************************************************************
-                        Links colors and highlighting: 
- ***************************************************************************/
-
-a { text-decoration: none; }
-a:hover { text-decoration: underline; }
-a:link { color: #0048b3; }
-a:visited { color: #002a6a; }
-
-
-/***************************************************************************
-                              Table of contents:
- ***************************************************************************/
-
-div.toc
-{
-    font-size: 90%;
-}
-
-div.toc dl
-{
-    margin-top: 0em;
-    margin-bottom: 0em;
-}
-
-
-/***************************************************************************
-                               Special elements:
- ***************************************************************************/
-
-tt, code
-{
-    color: #400000;
-}
-
-.term
-{
-    font-weight: bold;
-    
-}
-
-div.variablelist dd p, div.glosslist dd p
-{
-    margin-top: 0em;
-}
-
-div.variablelist dd, div.glosslist dd
-{
-    margin-left: 1.5em;
-}
-
-div.glosslist dt
-{
-    font-style: italic;
-}
-
-.varname
-{
-    color: #400000;
-}
-
-span.command strong
-{
-    font-weight: normal;
-    color: #400000;
-}
-
-div.calloutlist table
-{
-}
-
-table
-{
-    border-collapse: collapse;
-}
-
-div.affiliation
-{
-    font-style: italic;
-}

local.mk

@@ -2,11 +2,15 @@ ifeq ($(MAKECMDGOALS), dist)
   dist-files += $(shell cat .dist-files)
 endif
 
-dist-files += configure config.h.in nix.spec perl/configure
+dist-files += configure config.h.in perl/configure
 
 clean-files += Makefile.config
 
-GLOBAL_CXXFLAGS += -I . -I src -I src/libutil -I src/libstore -I src/libmain -I src/libexpr -I src/nix
+GLOBAL_CXXFLAGS += -Wno-deprecated-declarations
 
 $(foreach i, config.h $(call rwildcard, src/lib*, *.hh), \
   $(eval $(call install-file-in, $(i), $(includedir)/nix, 0644)))
+
+$(GCH) $(PCH): src/libutil/util.hh config.h
+
+GCH_CXXFLAGS = -I src/libutil

m4/ax_cxx_compile_stdcxx.m4

@@ -0,0 +1,951 @@
+# ===========================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CXX_COMPILE_STDCXX(VERSION, [ext|noext], [mandatory|optional])
+#
+# DESCRIPTION
+#
+#   Check for baseline language coverage in the compiler for the specified
+#   version of the C++ standard.  If necessary, add switches to CXX and
+#   CXXCPP to enable support.  VERSION may be '11' (for the C++11 standard)
+#   or '14' (for the C++14 standard).
+#
+#   The second argument, if specified, indicates whether you insist on an
+#   extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g.
+#   -std=c++11).  If neither is specified, you get whatever works, with
+#   preference for an extended mode.
+#
+#   The third argument, if specified 'mandatory' or if left unspecified,
+#   indicates that baseline support for the specified C++ standard is
+#   required and that the macro should error out if no mode with that
+#   support is found.  If specified 'optional', then configuration proceeds
+#   regardless, after defining HAVE_CXX${VERSION} if and only if a
+#   supporting mode is found.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com>
+#   Copyright (c) 2012 Zack Weinberg <zackw@panix.com>
+#   Copyright (c) 2013 Roy Stogner <roystgnr@ices.utexas.edu>
+#   Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov@google.com>
+#   Copyright (c) 2015 Paul Norman <penorman@mac.com>
+#   Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
+#   Copyright (c) 2016, 2018 Krzesimir Nowak <qdlacz@gmail.com>
+#   Copyright (c) 2019 Enji Cooper <yaneurabeya@gmail.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved.  This file is offered as-is, without any
+#   warranty.
+
+#serial 11
+
+dnl  This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro
+dnl  (serial version number 13).
+
+AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
+  m4_if([$1], [11], [ax_cxx_compile_alternatives="11 0x"],
+        [$1], [14], [ax_cxx_compile_alternatives="14 1y"],
+        [$1], [17], [ax_cxx_compile_alternatives="17 1z"],
+        [m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl
+  m4_if([$2], [], [],
+        [$2], [ext], [],
+        [$2], [noext], [],
+        [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX])])dnl
+  m4_if([$3], [], [ax_cxx_compile_cxx$1_required=true],
+        [$3], [mandatory], [ax_cxx_compile_cxx$1_required=true],
+        [$3], [optional], [ax_cxx_compile_cxx$1_required=false],
+        [m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])])
+  AC_LANG_PUSH([C++])dnl
+  ac_success=no
+
+  m4_if([$2], [noext], [], [dnl
+  if test x$ac_success = xno; then
+    for alternative in ${ax_cxx_compile_alternatives}; do
+      switch="-std=gnu++${alternative}"
+      cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch])
+      AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch,
+                     $cachevar,
+        [ac_save_CXX="$CXX"
+         CXX="$CXX $switch"
+         AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
+          [eval $cachevar=yes],
+          [eval $cachevar=no])
+         CXX="$ac_save_CXX"])
+      if eval test x\$$cachevar = xyes; then
+        CXX="$CXX $switch"
+        if test -n "$CXXCPP" ; then
+          CXXCPP="$CXXCPP $switch"
+        fi
+        ac_success=yes
+        break
+      fi
+    done
+  fi])
+
+  m4_if([$2], [ext], [], [dnl
+  if test x$ac_success = xno; then
+    dnl HP's aCC needs +std=c++11 according to:
+    dnl http://h21007.www2.hp.com/portal/download/files/unprot/aCxx/PDF_Release_Notes/769149-001.pdf
+    dnl Cray's crayCC needs "-h std=c++11"
+    for alternative in ${ax_cxx_compile_alternatives}; do
+      for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do
+        cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch])
+        AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch,
+                       $cachevar,
+          [ac_save_CXX="$CXX"
+           CXX="$CXX $switch"
+           AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
+            [eval $cachevar=yes],
+            [eval $cachevar=no])
+           CXX="$ac_save_CXX"])
+        if eval test x\$$cachevar = xyes; then
+          CXX="$CXX $switch"
+          if test -n "$CXXCPP" ; then
+            CXXCPP="$CXXCPP $switch"
+          fi
+          ac_success=yes
+          break
+        fi
+      done
+      if test x$ac_success = xyes; then
+        break
+      fi
+    done
+  fi])
+  AC_LANG_POP([C++])
+  if test x$ax_cxx_compile_cxx$1_required = xtrue; then
+    if test x$ac_success = xno; then
+      AC_MSG_ERROR([*** A compiler with support for C++$1 language features is required.])
+    fi
+  fi
+  if test x$ac_success = xno; then
+    HAVE_CXX$1=0
+    AC_MSG_NOTICE([No compiler with C++$1 support was found])
+  else
+    HAVE_CXX$1=1
+    AC_DEFINE(HAVE_CXX$1,1,
+              [define if the compiler supports basic C++$1 syntax])
+  fi
+  AC_SUBST(HAVE_CXX$1)
+])
+
+
+dnl  Test body for checking C++11 support
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_11],
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
+)
+
+
+dnl  Test body for checking C++14 support
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14],
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_14
+)
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_17],
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_14
+  _AX_CXX_COMPILE_STDCXX_testbody_new_in_17
+)
+
+dnl  Tests for new features in C++11
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[
+
+// If the compiler admits that it is not ready for C++11, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201103L
+
+#error "This is not a C++11 compiler"
+
+#else
+
+namespace cxx11
+{
+
+  namespace test_static_assert
+  {
+
+    template <typename T>
+    struct check
+    {
+      static_assert(sizeof(int) <= sizeof(T), "not big enough");
+    };
+
+  }
+
+  namespace test_final_override
+  {
+
+    struct Base
+    {
+      virtual ~Base() {}
+      virtual void f() {}
+    };
+
+    struct Derived : public Base
+    {
+      virtual ~Derived() override {}
+      virtual void f() override {}
+    };
+
+  }
+
+  namespace test_double_right_angle_brackets
+  {
+
+    template < typename T >
+    struct check {};
+
+    typedef check<void> single_type;
+    typedef check<check<void>> double_type;
+    typedef check<check<check<void>>> triple_type;
+    typedef check<check<check<check<void>>>> quadruple_type;
+
+  }
+
+  namespace test_decltype
+  {
+
+    int
+    f()
+    {
+      int a = 1;
+      decltype(a) b = 2;
+      return a + b;
+    }
+
+  }
+
+  namespace test_type_deduction
+  {
+
+    template < typename T1, typename T2 >
+    struct is_same
+    {
+      static const bool value = false;
+    };
+
+    template < typename T >
+    struct is_same<T, T>
+    {
+      static const bool value = true;
+    };
+
+    template < typename T1, typename T2 >
+    auto
+    add(T1 a1, T2 a2) -> decltype(a1 + a2)
+    {
+      return a1 + a2;
+    }
+
+    int
+    test(const int c, volatile int v)
+    {
+      static_assert(is_same<int, decltype(0)>::value == true, "");
+      static_assert(is_same<int, decltype(c)>::value == false, "");
+      static_assert(is_same<int, decltype(v)>::value == false, "");
+      auto ac = c;
+      auto av = v;
+      auto sumi = ac + av + 'x';
+      auto sumf = ac + av + 1.0;
+      static_assert(is_same<int, decltype(ac)>::value == true, "");
+      static_assert(is_same<int, decltype(av)>::value == true, "");
+      static_assert(is_same<int, decltype(sumi)>::value == true, "");
+      static_assert(is_same<int, decltype(sumf)>::value == false, "");
+      static_assert(is_same<int, decltype(add(c, v))>::value == true, "");
+      return (sumf > 0.0) ? sumi : add(c, v);
+    }
+
+  }
+
+  namespace test_noexcept
+  {
+
+    int f() { return 0; }
+    int g() noexcept { return 0; }
+
+    static_assert(noexcept(f()) == false, "");
+    static_assert(noexcept(g()) == true, "");
+
+  }
+
+  namespace test_constexpr
+  {
+
+    template < typename CharT >
+    unsigned long constexpr
+    strlen_c_r(const CharT *const s, const unsigned long acc) noexcept
+    {
+      return *s ? strlen_c_r(s + 1, acc + 1) : acc;
+    }
+
+    template < typename CharT >
+    unsigned long constexpr
+    strlen_c(const CharT *const s) noexcept
+    {
+      return strlen_c_r(s, 0UL);
+    }
+
+    static_assert(strlen_c("") == 0UL, "");
+    static_assert(strlen_c("1") == 1UL, "");
+    static_assert(strlen_c("example") == 7UL, "");
+    static_assert(strlen_c("another\0example") == 7UL, "");
+
+  }
+
+  namespace test_rvalue_references
+  {
+
+    template < int N >
+    struct answer
+    {
+      static constexpr int value = N;
+    };
+
+    answer<1> f(int&)       { return answer<1>(); }
+    answer<2> f(const int&) { return answer<2>(); }
+    answer<3> f(int&&)      { return answer<3>(); }
+
+    void
+    test()
+    {
+      int i = 0;
+      const int c = 0;
+      static_assert(decltype(f(i))::value == 1, "");
+      static_assert(decltype(f(c))::value == 2, "");
+      static_assert(decltype(f(0))::value == 3, "");
+    }
+
+  }
+
+  namespace test_uniform_initialization
+  {
+
+    struct test
+    {
+      static const int zero {};
+      static const int one {1};
+    };
+
+    static_assert(test::zero == 0, "");
+    static_assert(test::one == 1, "");
+
+  }
+
+  namespace test_lambdas
+  {
+
+    void
+    test1()
+    {
+      auto lambda1 = [](){};
+      auto lambda2 = lambda1;
+      lambda1();
+      lambda2();
+    }
+
+    int
+    test2()
+    {
+      auto a = [](int i, int j){ return i + j; }(1, 2);
+      auto b = []() -> int { return '0'; }();
+      auto c = [=](){ return a + b; }();
+      auto d = [&](){ return c; }();
+      auto e = [a, &b](int x) mutable {
+        const auto identity = [](int y){ return y; };
+        for (auto i = 0; i < a; ++i)
+          a += b--;
+        return x + identity(a + b);
+      }(0);
+      return a + b + c + d + e;
+    }
+
+    int
+    test3()
+    {
+      const auto nullary = [](){ return 0; };
+      const auto unary = [](int x){ return x; };
+      using nullary_t = decltype(nullary);
+      using unary_t = decltype(unary);
+      const auto higher1st = [](nullary_t f){ return f(); };
+      const auto higher2nd = [unary](nullary_t f1){
+        return [unary, f1](unary_t f2){ return f2(unary(f1())); };
+      };
+      return higher1st(nullary) + higher2nd(nullary)(unary);
+    }
+
+  }
+
+  namespace test_variadic_templates
+  {
+
+    template <int...>
+    struct sum;
+
+    template <int N0, int... N1toN>
+    struct sum<N0, N1toN...>
+    {
+      static constexpr auto value = N0 + sum<N1toN...>::value;
+    };
+
+    template <>
+    struct sum<>
+    {
+      static constexpr auto value = 0;
+    };
+
+    static_assert(sum<>::value == 0, "");
+    static_assert(sum<1>::value == 1, "");
+    static_assert(sum<23>::value == 23, "");
+    static_assert(sum<1, 2>::value == 3, "");
+    static_assert(sum<5, 5, 11>::value == 21, "");
+    static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, "");
+
+  }
+
+  // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
+  // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function
+  // because of this.
+  namespace test_template_alias_sfinae
+  {
+
+    struct foo {};
+
+    template<typename T>
+    using member = typename T::member_type;
+
+    template<typename T>
+    void func(...) {}
+
+    template<typename T>
+    void func(member<T>*) {}
+
+    void test();
+
+    void test() { func<foo>(0); }
+
+  }
+
+}  // namespace cxx11
+
+#endif  // __cplusplus >= 201103L
+
+]])
+
+
+dnl  Tests for new features in C++14
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[
+
+// If the compiler admits that it is not ready for C++14, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201402L
+
+#error "This is not a C++14 compiler"
+
+#else
+
+namespace cxx14
+{
+
+  namespace test_polymorphic_lambdas
+  {
+
+    int
+    test()
+    {
+      const auto lambda = [](auto&&... args){
+        const auto istiny = [](auto x){
+          return (sizeof(x) == 1UL) ? 1 : 0;
+        };
+        const int aretiny[] = { istiny(args)... };
+        return aretiny[0];
+      };
+      return lambda(1, 1L, 1.0f, '1');
+    }
+
+  }
+
+  namespace test_binary_literals
+  {
+
+    constexpr auto ivii = 0b0000000000101010;
+    static_assert(ivii == 42, "wrong value");
+
+  }
+
+  namespace test_generalized_constexpr
+  {
+
+    template < typename CharT >
+    constexpr unsigned long
+    strlen_c(const CharT *const s) noexcept
+    {
+      auto length = 0UL;
+      for (auto p = s; *p; ++p)
+        ++length;
+      return length;
+    }
+
+    static_assert(strlen_c("") == 0UL, "");
+    static_assert(strlen_c("x") == 1UL, "");
+    static_assert(strlen_c("test") == 4UL, "");
+    static_assert(strlen_c("another\0test") == 7UL, "");
+
+  }
+
+  namespace test_lambda_init_capture
+  {
+
+    int
+    test()
+    {
+      auto x = 0;
+      const auto lambda1 = [a = x](int b){ return a + b; };
+      const auto lambda2 = [a = lambda1(x)](){ return a; };
+      return lambda2();
+    }
+
+  }
+
+  namespace test_digit_separators
+  {
+
+    constexpr auto ten_million = 100'000'000;
+    static_assert(ten_million == 100000000, "");
+
+  }
+
+  namespace test_return_type_deduction
+  {
+
+    auto f(int& x) { return x; }
+    decltype(auto) g(int& x) { return x; }
+
+    template < typename T1, typename T2 >
+    struct is_same
+    {
+      static constexpr auto value = false;
+    };
+
+    template < typename T >
+    struct is_same<T, T>
+    {
+      static constexpr auto value = true;
+    };
+
+    int
+    test()
+    {
+      auto x = 0;
+      static_assert(is_same<int, decltype(f(x))>::value, "");
+      static_assert(is_same<int&, decltype(g(x))>::value, "");
+      return x;
+    }
+
+  }
+
+}  // namespace cxx14
+
+#endif  // __cplusplus >= 201402L
+
+]])
+
+
+dnl  Tests for new features in C++17
+
+m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
+
+// If the compiler admits that it is not ready for C++17, why torture it?
+// Hopefully, this will speed up the test.
+
+#ifndef __cplusplus
+
+#error "This is not a C++ compiler"
+
+#elif __cplusplus < 201703L
+
+#error "This is not a C++17 compiler"
+
+#else
+
+#include <initializer_list>
+#include <utility>
+#include <type_traits>
+
+namespace cxx17
+{
+
+  namespace test_constexpr_lambdas
+  {
+
+    constexpr int foo = [](){return 42;}();
+
+  }
+
+  namespace test::nested_namespace::definitions
+  {
+
+  }
+
+  namespace test_fold_expression
+  {
+
+    template<typename... Args>
+    int multiply(Args... args)
+    {
+      return (args * ... * 1);
+    }
+
+    template<typename... Args>
+    bool all(Args... args)
+    {
+      return (args && ...);
+    }
+
+  }
+
+  namespace test_extended_static_assert
+  {
+
+    static_assert (true);
+
+  }
+
+  namespace test_auto_brace_init_list
+  {
+
+    auto foo = {5};
+    auto bar {5};
+
+    static_assert(std::is_same<std::initializer_list<int>, decltype(foo)>::value);
+    static_assert(std::is_same<int, decltype(bar)>::value);
+  }
+
+  namespace test_typename_in_template_template_parameter
+  {
+
+    template<template<typename> typename X> struct D;
+
+  }
+
+  namespace test_fallthrough_nodiscard_maybe_unused_attributes
+  {
+
+    int f1()
+    {
+      return 42;
+    }
+
+    [[nodiscard]] int f2()
+    {
+      [[maybe_unused]] auto unused = f1();
+
+      switch (f1())
+      {
+      case 17:
+        f1();
+        [[fallthrough]];
+      case 42:
+        f1();
+      }
+      return f1();
+    }
+
+  }
+
+  namespace test_extended_aggregate_initialization
+  {
+
+    struct base1
+    {
+      int b1, b2 = 42;
+    };
+
+    struct base2
+    {
+      base2() {
+        b3 = 42;
+      }
+      int b3;
+    };
+
+    struct derived : base1, base2
+    {
+        int d;
+    };
+
+    derived d1 {{1, 2}, {}, 4};  // full initialization
+    derived d2 {{}, {}, 4};      // value-initialized bases
+
+  }
+
+  namespace test_general_range_based_for_loop
+  {
+
+    struct iter
+    {
+      int i;
+
+      int& operator* ()
+      {
+        return i;
+      }
+
+      const int& operator* () const
+      {
+        return i;
+      }
+
+      iter& operator++()
+      {
+        ++i;
+        return *this;
+      }
+    };
+
+    struct sentinel
+    {
+      int i;
+    };
+
+    bool operator== (const iter& i, const sentinel& s)
+    {
+      return i.i == s.i;
+    }
+
+    bool operator!= (const iter& i, const sentinel& s)
+    {
+      return !(i == s);
+    }
+
+    struct range
+    {
+      iter begin() const
+      {
+        return {0};
+      }
+
+      sentinel end() const
+      {
+        return {5};
+      }
+    };
+
+    void f()
+    {
+      range r {};
+
+      for (auto i : r)
+      {
+        [[maybe_unused]] auto v = i;
+      }
+    }
+
+  }
+
+  namespace test_lambda_capture_asterisk_this_by_value
+  {
+
+    struct t
+    {
+      int i;
+      int foo()
+      {
+        return [*this]()
+        {
+          return i;
+        }();
+      }
+    };
+
+  }
+
+  namespace test_enum_class_construction
+  {
+
+    enum class byte : unsigned char
+    {};
+
+    byte foo {42};
+
+  }
+
+  namespace test_constexpr_if
+  {
+
+    template <bool cond>
+    int f ()
+    {
+      if constexpr(cond)
+      {
+        return 13;
+      }
+      else
+      {
+        return 42;
+      }
+    }
+
+  }
+
+  namespace test_selection_statement_with_initializer
+  {
+
+    int f()
+    {
+      return 13;
+    }
+
+    int f2()
+    {
+      if (auto i = f(); i > 0)
+      {
+        return 3;
+      }
+
+      switch (auto i = f(); i + 4)
+      {
+      case 17:
+        return 2;
+
+      default:
+        return 1;
+      }
+    }
+
+  }
+
+  namespace test_template_argument_deduction_for_class_templates
+  {
+
+    template <typename T1, typename T2>
+    struct pair
+    {
+      pair (T1 p1, T2 p2)
+        : m1 {p1},
+          m2 {p2}
+      {}
+
+      T1 m1;
+      T2 m2;
+    };
+
+    void f()
+    {
+      [[maybe_unused]] auto p = pair{13, 42u};
+    }
+
+  }
+
+  namespace test_non_type_auto_template_parameters
+  {
+
+    template <auto n>
+    struct B
+    {};
+
+    B<5> b1;
+    B<'a'> b2;
+
+  }
+
+  namespace test_structured_bindings
+  {
+
+    int arr[2] = { 1, 2 };
+    std::pair<int, int> pr = { 1, 2 };
+
+    auto f1() -> int(&)[2]
+    {
+      return arr;
+    }
+
+    auto f2() -> std::pair<int, int>&
+    {
+      return pr;
+    }
+
+    struct S
+    {
+      int x1 : 2;
+      volatile double y1;
+    };
+
+    S f3()
+    {
+      return {};
+    }
+
+    auto [ x1, y1 ] = f1();
+    auto& [ xr1, yr1 ] = f1();
+    auto [ x2, y2 ] = f2();
+    auto& [ xr2, yr2 ] = f2();
+    const auto [ x3, y3 ] = f3();
+
+  }
+
+  namespace test_exception_spec_type_system
+  {
+
+    struct Good {};
+    struct Bad {};
+
+    void g1() noexcept;
+    void g2();
+
+    template<typename T>
+    Bad
+    f(T*, T*);
+
+    template<typename T1, typename T2>
+    Good
+    f(T1*, T2*);
+
+    static_assert (std::is_same_v<Good, decltype(f(g1, g2))>);
+
+  }
+
+  namespace test_inline_variables
+  {
+
+    template<class T> void f(T)
+    {}
+
+    template<class T> inline T g(T)
+    {
+      return T{};
+    }
+
+    template<> inline void f<>(int)
+    {}
+
+    template<> int g<>(int)
+    {
+      return 5;
+    }
+
+  }
+
+}  // namespace cxx17
+
+#endif  // __cplusplus < 201703L
+
+]])

m4/ax_cxx_compile_stdcxx_17.m4

@@ -0,0 +1,35 @@
+# =============================================================================
+#  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx_17.html
+# =============================================================================
+#
+# SYNOPSIS
+#
+#   AX_CXX_COMPILE_STDCXX_17([ext|noext], [mandatory|optional])
+#
+# DESCRIPTION
+#
+#   Check for baseline language coverage in the compiler for the C++17
+#   standard; if necessary, add switches to CXX and CXXCPP to enable
+#   support.
+#
+#   This macro is a convenience alias for calling the AX_CXX_COMPILE_STDCXX
+#   macro with the version set to C++17.  The two optional arguments are
+#   forwarded literally as the second and third argument respectively.
+#   Please see the documentation for the AX_CXX_COMPILE_STDCXX macro for
+#   more information.  If you want to use this macro, you also need to
+#   download the ax_cxx_compile_stdcxx.m4 file.
+#
+# LICENSE
+#
+#   Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
+#   Copyright (c) 2016 Krzesimir Nowak <qdlacz@gmail.com>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 2
+
+AX_REQUIRE_DEFINED([AX_CXX_COMPILE_STDCXX])
+AC_DEFUN([AX_CXX_COMPILE_STDCXX_17], [AX_CXX_COMPILE_STDCXX([17], [$1], [$2])])

maintainers/upload-release.pl

@@ -44,7 +44,7 @@ print STDERR "Nix revision is $nixRev, version is $version\n";
 
 File::Path::make_path($releasesDir);
 if (system("mountpoint -q $releasesDir") != 0) {
-    system("sshfs hydra-mirror:/releases $releasesDir") == 0 or die;
+    system("sshfs hydra-mirror\@nixos.org:/releases $releasesDir") == 0 or die;
 }
 
 my $releaseDir = "$releasesDir/nix/$releaseName";
@@ -67,10 +67,10 @@ sub downloadFile {
     }
 
     my $sha256_expected = $buildInfo->{buildproducts}->{$productNr}->{sha256hash} or die;
-    my $sha256_actual = `nix hash-file --type sha256 '$dstFile'`;
+    my $sha256_actual = `nix hash-file --base16 --type sha256 '$dstFile'`;
     chomp $sha256_actual;
     if ($sha256_expected ne $sha256_actual) {
-        print STDERR "file $dstFile is corrupt\n";
+        print STDERR "file $dstFile is corrupt, got $sha256_actual, expected $sha256_expected\n";
         exit 1;
     }
 

misc/launchd/org.nixos.nix-daemon.plist.in

@@ -13,8 +13,12 @@
     <true/>
     <key>RunAtLoad</key>
     <true/>
-    <key>Program</key>
-    <string>@bindir@/nix-daemon</string>
+    <key>ProgramArguments</key>
+    <array>
+      <string>/bin/sh</string>
+      <string>-c</string>
+      <string>/bin/wait4path /nix/var/nix/profiles/default/bin/nix-daemon &amp;&amp; /nix/var/nix/profiles/default/bin/nix-daemon</string>
+    </array>
     <key>StandardErrorPath</key>
     <string>/var/log/nix-daemon.log</string>
     <key>StandardOutPath</key>

misc/systemd/nix-daemon.service.in

@@ -7,3 +7,6 @@ ConditionPathIsReadWrite=@localstatedir@/nix/daemon-socket
 [Service]
 ExecStart=@@bindir@/nix-daemon nix-daemon --daemon
 KillMode=process
+
+[Install]
+WantedBy=multi-user.target

mk/README.md

@@ -1,6 +0,0 @@
-This is a set of helper Makefiles for doing non-recursive builds with
-GNU Make.  The canonical source can be found at
-https://github.com/edolstra/make-rules.  You should copy the files
-into the `mk` subdirectory of your project.
-
-TODO: write more documentation.

mk/libraries.mk

@@ -91,7 +91,7 @@ define build-library
     $(1)_PATH := $$(_d)/$$($(1)_NAME).$(SO_EXT)
 
     $$($(1)_PATH): $$($(1)_OBJS) $$(_libs) | $$(_d)/
-	$$(trace-ld) $(CXX) -o $$(abspath $$@) -shared $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$($(1)_LDFLAGS_PROPAGATED) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE)) $$($(1)_LDFLAGS_UNINSTALLED)
+	$$(trace-ld) $(CXX) -o $$(abspath $$@) -shared $$(LDFLAGS) $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$($(1)_LDFLAGS_PROPAGATED) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE)) $$($(1)_LDFLAGS_UNINSTALLED)
 
     ifneq ($(OS), Darwin)
       $(1)_LDFLAGS_USE += -Wl,-rpath,$$(abspath $$(_d))
@@ -105,7 +105,7 @@ define build-library
     $$(eval $$(call create-dir, $$($(1)_INSTALL_DIR)))
 
     $$($(1)_INSTALL_PATH): $$($(1)_OBJS) $$(_libs_final) | $(DESTDIR)$$($(1)_INSTALL_DIR)/
-	$$(trace-ld) $(CXX) -o $$@ -shared $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$($(1)_LDFLAGS_PROPAGATED) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE_INSTALLED))
+	$$(trace-ld) $(CXX) -o $$@ -shared $$(LDFLAGS) $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$($(1)_LDFLAGS_PROPAGATED) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE_INSTALLED))
 
     $(1)_LDFLAGS_USE_INSTALLED += -L$$(DESTDIR)$$($(1)_INSTALL_DIR) -l$$(patsubst lib%,%,$$(strip $$($(1)_NAME)))
     ifneq ($(OS), Darwin)

mk/patterns.mk

@@ -1,10 +1,10 @@
 $(buildprefix)%.o: %.cc
 	@mkdir -p "$(dir $@)"
-	$(trace-cxx) $(CXX) -o $@ -c $< $(GLOBAL_CXXFLAGS) $(GLOBAL_CXXFLAGS_PCH) $(CXXFLAGS) $($@_CXXFLAGS) -MMD -MF $(call filename-to-dep, $@) -MP
+	$(trace-cxx) $(CXX) -o $@ -c $< $(GLOBAL_CXXFLAGS_PCH) $(GLOBAL_CXXFLAGS) $(CXXFLAGS) $($@_CXXFLAGS) -MMD -MF $(call filename-to-dep, $@) -MP
 
 $(buildprefix)%.o: %.cpp
 	@mkdir -p "$(dir $@)"
-	$(trace-cxx) $(CXX) -o $@ -c $< $(GLOBAL_CXXFLAGS) $(GLOBAL_CXXFLAGS_PCH) $(CXXFLAGS) $($@_CXXFLAGS) -MMD -MF $(call filename-to-dep, $@) -MP
+	$(trace-cxx) $(CXX) -o $@ -c $< $(GLOBAL_CXXFLAGS_PCH) $(GLOBAL_CXXFLAGS) $(CXXFLAGS) $($@_CXXFLAGS) -MMD -MF $(call filename-to-dep, $@) -MP
 
 $(buildprefix)%.o: %.c
 	@mkdir -p "$(dir $@)"

mk/precompiled-headers.mk

@@ -0,0 +1,42 @@
+PRECOMPILE_HEADERS ?= 1
+
+print-var-help += \
+  echo "  PRECOMPILE_HEADERS ($(PRECOMPILE_HEADERS)): Whether to use precompiled headers to speed up the build";
+
+GCH = $(buildprefix)precompiled-headers.h.gch
+
+$(GCH): precompiled-headers.h
+	@rm -f $@
+	@mkdir -p "$(dir $@)"
+	$(trace-gen) $(CXX) -x c++-header -o $@ $< $(GLOBAL_CXXFLAGS) $(GCH_CXXFLAGS)
+
+PCH = $(buildprefix)precompiled-headers.h.pch
+
+$(PCH): precompiled-headers.h
+	@rm -f $@
+	@mkdir -p "$(dir $@)"
+	$(trace-gen) $(CXX) -x c++-header -o $@ $< $(GLOBAL_CXXFLAGS) $(GCH_CXXFLAGS)
+
+clean-files += $(GCH) $(PCH)
+
+ifeq ($(PRECOMPILE_HEADERS), 1)
+
+  ifeq ($(CXX), g++)
+
+    GLOBAL_CXXFLAGS_PCH += -include $(buildprefix)precompiled-headers.h -Winvalid-pch
+
+    GLOBAL_ORDER_AFTER += $(GCH)
+
+  else ifeq ($(CXX), clang++)
+
+    GLOBAL_CXXFLAGS_PCH += -include-pch $(PCH) -Winvalid-pch
+
+    GLOBAL_ORDER_AFTER += $(PCH)
+
+  else
+
+    $(error Don't know how to precompile headers on $(CXX))
+
+  endif
+
+endif

mk/programs.mk

@@ -32,7 +32,7 @@ define build-program
   $$(eval $$(call create-dir, $$(_d)))
 
   $$($(1)_PATH): $$($(1)_OBJS) $$(_libs) | $$(_d)/
-	$$(trace-ld) $(CXX) -o $$@ $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE))
+	$$(trace-ld) $(CXX) -o $$@ $$(LDFLAGS) $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE))
 
   $(1)_INSTALL_DIR ?= $$(bindir)
   $(1)_INSTALL_PATH := $$($(1)_INSTALL_DIR)/$(1)
@@ -46,7 +46,7 @@ define build-program
     _libs_final := $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_INSTALL_PATH))
 
     $(DESTDIR)$$($(1)_INSTALL_PATH): $$($(1)_OBJS) $$(_libs_final) | $(DESTDIR)$$($(1)_INSTALL_DIR)/
-	$$(trace-ld) $(CXX) -o $$@ $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE_INSTALLED))
+	$$(trace-ld) $(CXX) -o $$@ $$(LDFLAGS) $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE_INSTALLED))
 
   else
 

nix-rust/Cargo.lock

@@ -0,0 +1,399 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "assert_matches"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "autocfg"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "bit-set"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bit-vec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "bit-vec"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "bitflags"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "byteorder"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "c2-chacha"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "ppv-lite86 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "cloudabi"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "fnv"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "fuchsia-cprng"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "getrandom"
+version = "0.1.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasi 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "hex"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "libc"
+version = "0.2.66"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "nix-rust"
+version = "0.1.0"
+dependencies = [
+ "assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proptest 0.9.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "num-traits"
+version = "0.2.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "proptest"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bit-set 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rusty-fork 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "quick-error"
+version = "1.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "rand"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_jitter 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_pcg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "getrandom 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_chacha 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "c2-chacha 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "rand_core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "getrandom 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_isaac"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_jitter"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_os"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_pcg"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_xorshift"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rdrand"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "redox_syscall"
+version = "0.1.56"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "remove_dir_all"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rusty-fork"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wait-timeout 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "tempfile"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)",
+ "remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wait-timeout"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wasi"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[metadata]
+"checksum assert_matches 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7deb0a829ca7bcfaf5da70b073a8d128619259a7be8216a355e23f00763059e5"
+"checksum autocfg 0.1.7 (registry+https://github.com/rust-lang/crates.io-index)" = "1d49d90015b3c36167a20fe2810c5cd875ad504b39cff3d4eae7977e6b7c1cb2"
+"checksum bit-set 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e84c238982c4b1e1ee668d136c510c67a13465279c0cb367ea6baf6310620a80"
+"checksum bit-vec 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f59bbe95d4e52a6398ec21238d31577f2b28a9d86807f06ca59d191d8440d0bb"
+"checksum bitflags 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+"checksum byteorder 1.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "a7c3dd8985a7111efc5c80b44e23ecdd8c007de8ade3b96595387e812b957cf5"
+"checksum c2-chacha 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "214238caa1bf3a496ec3392968969cab8549f96ff30652c9e56885329315f6bb"
+"checksum cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
+"checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
+"checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
+"checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
+"checksum getrandom 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "e7db7ca94ed4cd01190ceee0d8a8052f08a247aa1b469a7f68c6a3b71afcf407"
+"checksum hex 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)" = "805026a5d0141ffc30abb3be3173848ad46a1b1664fe632428479619a3644d77"
+"checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+"checksum libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)" = "d515b1f41455adea1313a4a2ac8a8a477634fbae63cc6100e3aebb207ce61558"
+"checksum num-traits 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)" = "d4c81ffc11c212fa327657cb19dd85eb7419e163b5b076bede2bdb5c974c07e4"
+"checksum ppv-lite86 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
+"checksum proptest 0.9.4 (registry+https://github.com/rust-lang/crates.io-index)" = "cf147e022eacf0c8a054ab864914a7602618adba841d800a9a9868a5237a529f"
+"checksum quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9274b940887ce9addde99c4eee6b5c44cc494b182b97e73dc8ffdcb3397fd3f0"
+"checksum rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)" = "6d71dacdc3c88c1fde3885a3be3fbab9f35724e6ce99467f7d9c5026132184ca"
+"checksum rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3ae1b169243eaf61759b8475a998f0a385e42042370f3a7dbaf35246eacc8412"
+"checksum rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "556d3a1ca6600bfcbab7c7c91ccb085ac7fbbcd70e008a98742e7847f4f7bcef"
+"checksum rand_chacha 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "03a2a90da8c7523f554344f921aa97283eadf6ac484a6d2a7d0212fa7f8d6853"
+"checksum rand_core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6fdeb83b075e8266dcc8762c22776f6877a63111121f5f8c7411e5be7eed4b"
+"checksum rand_core 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "9c33a3c44ca05fa6f1807d8e6743f3824e8509beca625669633be0acbdf509dc"
+"checksum rand_core 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "90bde5296fc891b0cef12a6d03ddccc162ce7b2aff54160af9338f8d40df6d19"
+"checksum rand_hc 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7b40677c7be09ae76218dc623efbf7b18e34bced3f38883af07bb75630a21bc4"
+"checksum rand_hc 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ca3129af7b92a17112d59ad498c6f81eaf463253766b90396d39ea7a39d6613c"
+"checksum rand_isaac 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ded997c9d5f13925be2a6fd7e66bf1872597f759fd9dd93513dd7e92e5a5ee08"
+"checksum rand_jitter 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)" = "1166d5c91dc97b88d1decc3285bb0a99ed84b05cfd0bc2341bdf2d43fc41e39b"
+"checksum rand_os 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "7b75f676a1e053fc562eafbb47838d67c84801e38fc1ba459e8f180deabd5071"
+"checksum rand_pcg 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "abf9b09b01790cfe0364f52bf32995ea3c39f4d2dd011eac241d2914146d0b44"
+"checksum rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cbf7e9e623549b0e21f6e97cf8ecf247c1a8fd2e8a992ae265314300b2455d5c"
+"checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
+"checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
+"checksum regex-syntax 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)" = "11a7e20d1cce64ef2fed88b66d347f88bd9babb82845b2b858f3edbf59a4f716"
+"checksum remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4a83fa3702a688b9359eccba92d153ac33fd2e8462f9e0e3fdf155239ea7792e"
+"checksum rusty-fork 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "3dd93264e10c577503e926bd1430193eeb5d21b059148910082245309b424fae"
+"checksum tempfile 3.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7a6e24d9338a0a5be79593e2fa15a648add6138caa803e2d5bc782c371732ca9"
+"checksum wait-timeout 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9f200f5b12eb75f8c1ed65abd4b2db8a6e1b138a20de009dacee265a2498f3f6"
+"checksum wasi 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b89c3ce4ce14bdc6fb6beaf9ec7928ca331de5df7e5ea278375642a2f478570d"
+"checksum winapi 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)" = "8093091eeb260906a183e6ae1abdba2ef5ef2257a21801128899c3fc699229c6"
+"checksum winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
+"checksum winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"

nix-rust/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "nix-rust"
+version = "0.1.0"
+authors = ["Eelco Dolstra <edolstra@gmail.com>"]
+edition = "2018"
+
+[lib]
+name = "nixrust"
+crate-type = ["cdylib"]
+
+[dependencies]
+libc = "0.2"
+#futures-preview = { version = "=0.3.0-alpha.19" }
+#hyper = "0.13.0-alpha.4"
+#http = "0.1"
+#tokio = { version = "0.2.0-alpha.6", default-features = false, features = ["rt-full"] }
+lazy_static = "1.4"
+#byteorder = "1.3"
+
+[dev-dependencies]
+hex = "0.3"
+assert_matches = "1.3"
+proptest = "0.9"

nix-rust/local.mk

@@ -0,0 +1,45 @@
+ifeq ($(OPTIMIZE), 1)
+  RUST_MODE = --release
+  RUST_DIR = release
+else
+  RUST_MODE =
+  RUST_DIR = debug
+endif
+
+libnixrust_PATH := $(d)/target/$(RUST_DIR)/libnixrust.$(SO_EXT)
+libnixrust_INSTALL_PATH := $(libdir)/libnixrust.$(SO_EXT)
+libnixrust_LDFLAGS_USE := -L$(d)/target/$(RUST_DIR) -lnixrust -ldl
+libnixrust_LDFLAGS_USE_INSTALLED := -L$(libdir) -lnixrust -ldl
+
+ifeq ($(OS), Darwin)
+libnixrust_BUILD_FLAGS = NIX_LDFLAGS="-undefined dynamic_lookup"
+else
+libnixrust_LDFLAGS_USE += -Wl,-rpath,$(abspath $(d)/target/$(RUST_DIR))
+libnixrust_LDFLAGS_USE_INSTALLED += -Wl,-rpath,$(libdir)
+endif
+
+$(libnixrust_PATH): $(call rwildcard, $(d)/src, *.rs) $(d)/Cargo.toml
+	$(trace-gen) cd nix-rust && CARGO_HOME=$$(if [[ -d vendor ]]; then echo vendor; fi) \
+	$(libnixrust_BUILD_FLAGS) \
+	  cargo build $(RUST_MODE) $$(if [[ -d vendor ]]; then echo --offline; fi) \
+	&& touch target/$(RUST_DIR)/libnixrust.$(SO_EXT)
+
+$(libnixrust_INSTALL_PATH): $(libnixrust_PATH)
+	$(target-gen) cp $^ $@
+ifeq ($(OS), Darwin)
+	install_name_tool -id $@ $@
+endif
+
+dist-files += $(d)/vendor
+
+clean: clean-rust
+
+clean-rust:
+	$(suppress) rm -rfv nix-rust/target
+
+ifneq ($(OS), Darwin)
+check: rust-tests
+
+rust-tests:
+	cd nix-rust && CARGO_HOME=$$(if [[ -d vendor ]]; then echo vendor; fi) cargo test --release $$(if [[ -d vendor ]]; then echo --offline; fi)
+endif

nix-rust/src/c.rs

@@ -0,0 +1,77 @@
+use super::{error, store::path, store::StorePath, util};
+
+#[no_mangle]
+pub unsafe extern "C" fn ffi_String_new(s: &str, out: *mut String) {
+    // FIXME: check whether 's' is valid UTF-8?
+    out.write(s.to_string())
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn ffi_String_drop(self_: *mut String) {
+    std::ptr::drop_in_place(self_);
+}
+
+#[no_mangle]
+pub extern "C" fn ffi_StorePath_new(
+    path: &str,
+    store_dir: &str,
+) -> Result<StorePath, error::CppException> {
+    StorePath::new(std::path::Path::new(path), std::path::Path::new(store_dir))
+        .map_err(|err| err.into())
+}
+
+#[no_mangle]
+pub extern "C" fn ffi_StorePath_new2(
+    hash: &[u8; crate::store::path::STORE_PATH_HASH_BYTES],
+    name: &str,
+) -> Result<StorePath, error::CppException> {
+    StorePath::from_parts(*hash, name).map_err(|err| err.into())
+}
+
+#[no_mangle]
+pub extern "C" fn ffi_StorePath_fromBaseName(
+    base_name: &str,
+) -> Result<StorePath, error::CppException> {
+    StorePath::new_from_base_name(base_name).map_err(|err| err.into())
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn ffi_StorePath_drop(self_: *mut StorePath) {
+    std::ptr::drop_in_place(self_);
+}
+
+#[no_mangle]
+pub extern "C" fn ffi_StorePath_to_string(self_: &StorePath) -> Vec<u8> {
+    let mut buf = vec![0; path::STORE_PATH_HASH_CHARS + 1 + self_.name.name().len()];
+    util::base32::encode_into(self_.hash.hash(), &mut buf[0..path::STORE_PATH_HASH_CHARS]);
+    buf[path::STORE_PATH_HASH_CHARS] = b'-';
+    buf[path::STORE_PATH_HASH_CHARS + 1..].clone_from_slice(self_.name.name().as_bytes());
+    buf
+}
+
+#[no_mangle]
+pub extern "C" fn ffi_StorePath_less_than(a: &StorePath, b: &StorePath) -> bool {
+    a < b
+}
+
+#[no_mangle]
+pub extern "C" fn ffi_StorePath_eq(a: &StorePath, b: &StorePath) -> bool {
+    a == b
+}
+
+#[no_mangle]
+pub extern "C" fn ffi_StorePath_clone(self_: &StorePath) -> StorePath {
+    self_.clone()
+}
+
+#[no_mangle]
+pub extern "C" fn ffi_StorePath_name(self_: &StorePath) -> &str {
+    self_.name.name()
+}
+
+#[no_mangle]
+pub extern "C" fn ffi_StorePath_hash_data(
+    self_: &StorePath,
+) -> &[u8; crate::store::path::STORE_PATH_HASH_BYTES] {
+    self_.hash.hash()
+}

nix-rust/src/error.rs

@@ -0,0 +1,118 @@
+use std::fmt;
+
+#[derive(Debug)]
+pub enum Error {
+    InvalidPath(crate::store::StorePath),
+    BadStorePath(std::path::PathBuf),
+    NotInStore(std::path::PathBuf),
+    BadNarInfo,
+    BadBase32,
+    StorePathNameEmpty,
+    StorePathNameTooLong,
+    BadStorePathName,
+    NarSizeFieldTooBig,
+    BadNarString,
+    BadNarPadding,
+    BadNarVersionMagic,
+    MissingNarOpenTag,
+    MissingNarCloseTag,
+    MissingNarField,
+    BadNarField(String),
+    BadExecutableField,
+    IOError(std::io::Error),
+    #[cfg(unused)]
+    HttpError(hyper::error::Error),
+    Misc(String),
+    #[cfg(not(test))]
+    Foreign(CppException),
+    BadTarFileMemberName(String),
+}
+
+impl From<std::io::Error> for Error {
+    fn from(err: std::io::Error) -> Self {
+        Error::IOError(err)
+    }
+}
+
+#[cfg(unused)]
+impl From<hyper::error::Error> for Error {
+    fn from(err: hyper::error::Error) -> Self {
+        Error::HttpError(err)
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Error::InvalidPath(_) => write!(f, "invalid path"),
+            Error::BadNarInfo => write!(f, ".narinfo file is corrupt"),
+            Error::BadStorePath(path) => write!(f, "path '{}' is not a store path", path.display()),
+            Error::NotInStore(path) => {
+                write!(f, "path '{}' is not in the Nix store", path.display())
+            }
+            Error::BadBase32 => write!(f, "invalid base32 string"),
+            Error::StorePathNameEmpty => write!(f, "store path name is empty"),
+            Error::StorePathNameTooLong => {
+                write!(f, "store path name is longer than 211 characters")
+            }
+            Error::BadStorePathName => write!(f, "store path name contains forbidden character"),
+            Error::NarSizeFieldTooBig => write!(f, "size field in NAR is too big"),
+            Error::BadNarString => write!(f, "NAR string is not valid UTF-8"),
+            Error::BadNarPadding => write!(f, "NAR padding is not zero"),
+            Error::BadNarVersionMagic => write!(f, "unsupported NAR version"),
+            Error::MissingNarOpenTag => write!(f, "NAR open tag is missing"),
+            Error::MissingNarCloseTag => write!(f, "NAR close tag is missing"),
+            Error::MissingNarField => write!(f, "expected NAR field is missing"),
+            Error::BadNarField(s) => write!(f, "unrecognized NAR field '{}'", s),
+            Error::BadExecutableField => write!(f, "bad 'executable' field in NAR"),
+            Error::IOError(err) => write!(f, "I/O error: {}", err),
+            #[cfg(unused)]
+            Error::HttpError(err) => write!(f, "HTTP error: {}", err),
+            #[cfg(not(test))]
+            Error::Foreign(_) => write!(f, "<C++ exception>"), // FIXME
+            Error::Misc(s) => write!(f, "{}", s),
+            Error::BadTarFileMemberName(s) => {
+                write!(f, "tar archive contains illegal file name '{}'", s)
+            }
+        }
+    }
+}
+
+#[cfg(not(test))]
+impl From<Error> for CppException {
+    fn from(err: Error) -> Self {
+        match err {
+            Error::Foreign(ex) => ex,
+            _ => CppException::new(&err.to_string()),
+        }
+    }
+}
+
+#[cfg(not(test))]
+#[repr(C)]
+#[derive(Debug)]
+pub struct CppException(*const libc::c_void); // == std::exception_ptr*
+
+#[cfg(not(test))]
+impl CppException {
+    fn new(s: &str) -> Self {
+        Self(unsafe { make_error(s) })
+    }
+}
+
+#[cfg(not(test))]
+impl Drop for CppException {
+    fn drop(&mut self) {
+        unsafe {
+            destroy_error(self.0);
+        }
+    }
+}
+
+#[cfg(not(test))]
+extern "C" {
+    #[allow(improper_ctypes)] // YOLO
+    fn make_error(s: &str) -> *const libc::c_void;
+
+    fn destroy_error(exc: *const libc::c_void);
+}

nix-rust/src/lib.rs

@@ -0,0 +1,9 @@
+#[cfg(not(test))]
+mod c;
+mod error;
+#[cfg(unused)]
+mod nar;
+mod store;
+mod util;
+
+pub use error::Error;

nix-rust/src/nar.rs

@@ -0,0 +1,126 @@
+use crate::Error;
+use byteorder::{LittleEndian, ReadBytesExt};
+use std::convert::TryFrom;
+use std::io::Read;
+
+pub fn parse<R: Read>(input: &mut R) -> Result<(), Error> {
+    if String::read(input)? != NAR_VERSION_MAGIC {
+        return Err(Error::BadNarVersionMagic);
+    }
+
+    parse_file(input)
+}
+
+const NAR_VERSION_MAGIC: &str = "nix-archive-1";
+
+fn parse_file<R: Read>(input: &mut R) -> Result<(), Error> {
+    if String::read(input)? != "(" {
+        return Err(Error::MissingNarOpenTag);
+    }
+
+    if String::read(input)? != "type" {
+        return Err(Error::MissingNarField);
+    }
+
+    match String::read(input)?.as_ref() {
+        "regular" => {
+            let mut _executable = false;
+            let mut tag = String::read(input)?;
+            if tag == "executable" {
+                _executable = true;
+                if String::read(input)? != "" {
+                    return Err(Error::BadExecutableField);
+                }
+                tag = String::read(input)?;
+            }
+            if tag != "contents" {
+                return Err(Error::MissingNarField);
+            }
+            let _contents = Vec::<u8>::read(input)?;
+            if String::read(input)? != ")" {
+                return Err(Error::MissingNarCloseTag);
+            }
+        }
+        "directory" => loop {
+            match String::read(input)?.as_ref() {
+                "entry" => {
+                    if String::read(input)? != "(" {
+                        return Err(Error::MissingNarOpenTag);
+                    }
+                    if String::read(input)? != "name" {
+                        return Err(Error::MissingNarField);
+                    }
+                    let _name = String::read(input)?;
+                    if String::read(input)? != "node" {
+                        return Err(Error::MissingNarField);
+                    }
+                    parse_file(input)?;
+                    let tag = String::read(input)?;
+                    if tag != ")" {
+                        return Err(Error::MissingNarCloseTag);
+                    }
+                }
+                ")" => break,
+                s => return Err(Error::BadNarField(s.into())),
+            }
+        },
+        "symlink" => {
+            if String::read(input)? != "target" {
+                return Err(Error::MissingNarField);
+            }
+            let _target = String::read(input)?;
+            if String::read(input)? != ")" {
+                return Err(Error::MissingNarCloseTag);
+            }
+        }
+        s => return Err(Error::BadNarField(s.into())),
+    }
+
+    Ok(())
+}
+
+trait Deserialize: Sized {
+    fn read<R: Read>(input: &mut R) -> Result<Self, Error>;
+}
+
+impl Deserialize for String {
+    fn read<R: Read>(input: &mut R) -> Result<Self, Error> {
+        let buf = Deserialize::read(input)?;
+        Ok(String::from_utf8(buf).map_err(|_| Error::BadNarString)?)
+    }
+}
+
+impl Deserialize for Vec<u8> {
+    fn read<R: Read>(input: &mut R) -> Result<Self, Error> {
+        let n: usize = Deserialize::read(input)?;
+        let mut buf = vec![0; n];
+        input.read_exact(&mut buf)?;
+        skip_padding(input, n)?;
+        Ok(buf)
+    }
+}
+
+fn skip_padding<R: Read>(input: &mut R, len: usize) -> Result<(), Error> {
+    if len % 8 != 0 {
+        let mut buf = [0; 8];
+        let buf = &mut buf[0..8 - (len % 8)];
+        input.read_exact(buf)?;
+        if !buf.iter().all(|b| *b == 0) {
+            return Err(Error::BadNarPadding);
+        }
+    }
+    Ok(())
+}
+
+impl Deserialize for u64 {
+    fn read<R: Read>(input: &mut R) -> Result<Self, Error> {
+        Ok(input.read_u64::<LittleEndian>()?)
+    }
+}
+
+impl Deserialize for usize {
+    fn read<R: Read>(input: &mut R) -> Result<Self, Error> {
+        let n: u64 = Deserialize::read(input)?;
+        Ok(usize::try_from(n).map_err(|_| Error::NarSizeFieldTooBig)?)
+    }
+}

nix-rust/src/store/binary_cache_store.rs

@@ -0,0 +1,48 @@
+use super::{PathInfo, Store, StorePath};
+use crate::Error;
+use hyper::client::Client;
+
+pub struct BinaryCacheStore {
+    base_uri: String,
+    client: Client<hyper::client::HttpConnector, hyper::Body>,
+}
+
+impl BinaryCacheStore {
+    pub fn new(base_uri: String) -> Self {
+        Self {
+            base_uri,
+            client: Client::new(),
+        }
+    }
+}
+
+impl Store for BinaryCacheStore {
+    fn query_path_info(
+        &self,
+        path: &StorePath,
+    ) -> std::pin::Pin<Box<dyn std::future::Future<Output = Result<PathInfo, Error>> + Send>> {
+        let uri = format!("{}/{}.narinfo", self.base_uri.clone(), path.hash);
+        let path = path.clone();
+        let client = self.client.clone();
+        let store_dir = self.store_dir().to_string();
+
+        Box::pin(async move {
+            let response = client.get(uri.parse::<hyper::Uri>().unwrap()).await?;
+
+            if response.status() == hyper::StatusCode::NOT_FOUND
+                || response.status() == hyper::StatusCode::FORBIDDEN
+            {
+                return Err(Error::InvalidPath(path));
+            }
+
+            let mut body = response.into_body();
+
+            let mut bytes = Vec::new();
+            while let Some(next) = body.next().await {
+                bytes.extend(next?);
+            }
+
+            PathInfo::parse_nar_info(std::str::from_utf8(&bytes).unwrap(), &store_dir)
+        })
+    }
+}

nix-rust/src/store/mod.rs

@@ -0,0 +1,17 @@
+pub mod path;
+
+#[cfg(unused)]
+mod binary_cache_store;
+#[cfg(unused)]
+mod path_info;
+#[cfg(unused)]
+mod store;
+
+pub use path::{StorePath, StorePathHash, StorePathName};
+
+#[cfg(unused)]
+pub use binary_cache_store::BinaryCacheStore;
+#[cfg(unused)]
+pub use path_info::PathInfo;
+#[cfg(unused)]
+pub use store::Store;

nix-rust/src/store/path.rs

@@ -0,0 +1,225 @@
+use crate::error::Error;
+use crate::util::base32;
+use std::fmt;
+use std::path::Path;
+
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
+pub struct StorePath {
+    pub hash: StorePathHash,
+    pub name: StorePathName,
+}
+
+pub const STORE_PATH_HASH_BYTES: usize = 20;
+pub const STORE_PATH_HASH_CHARS: usize = 32;
+
+impl StorePath {
+    pub fn new(path: &Path, store_dir: &Path) -> Result<Self, Error> {
+        if path.parent() != Some(store_dir) {
+            return Err(Error::NotInStore(path.into()));
+        }
+        Self::new_from_base_name(
+            path.file_name()
+                .ok_or(Error::BadStorePath(path.into()))?
+                .to_str()
+                .ok_or(Error::BadStorePath(path.into()))?,
+        )
+    }
+
+    pub fn from_parts(hash: [u8; STORE_PATH_HASH_BYTES], name: &str) -> Result<Self, Error> {
+        Ok(StorePath {
+            hash: StorePathHash(hash),
+            name: StorePathName::new(name)?,
+        })
+    }
+
+    pub fn new_from_base_name(base_name: &str) -> Result<Self, Error> {
+        if base_name.len() < STORE_PATH_HASH_CHARS + 1
+            || base_name.as_bytes()[STORE_PATH_HASH_CHARS] != '-' as u8
+        {
+            return Err(Error::BadStorePath(base_name.into()));
+        }
+
+        Ok(StorePath {
+            hash: StorePathHash::new(&base_name[0..STORE_PATH_HASH_CHARS])?,
+            name: StorePathName::new(&base_name[STORE_PATH_HASH_CHARS + 1..])?,
+        })
+    }
+}
+
+impl fmt::Display for StorePath {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}-{}", self.hash, self.name)
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct StorePathHash([u8; STORE_PATH_HASH_BYTES]);
+
+impl StorePathHash {
+    pub fn new(s: &str) -> Result<Self, Error> {
+        assert_eq!(s.len(), STORE_PATH_HASH_CHARS);
+        let v = base32::decode(s)?;
+        assert_eq!(v.len(), STORE_PATH_HASH_BYTES);
+        let mut bytes: [u8; 20] = Default::default();
+        bytes.copy_from_slice(&v[0..STORE_PATH_HASH_BYTES]);
+        Ok(Self(bytes))
+    }
+
+    pub fn hash<'a>(&'a self) -> &'a [u8; STORE_PATH_HASH_BYTES] {
+        &self.0
+    }
+}
+
+impl fmt::Display for StorePathHash {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut buf = vec![0; STORE_PATH_HASH_CHARS];
+        base32::encode_into(&self.0, &mut buf);
+        f.write_str(std::str::from_utf8(&buf).unwrap())
+    }
+}
+
+impl Ord for StorePathHash {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        // Historically we've sorted store paths by their base32
+        // serialization, but our base32 encodes bytes in reverse
+        // order. So compare them in reverse order as well.
+        self.0.iter().rev().cmp(other.0.iter().rev())
+    }
+}
+
+impl PartialOrd for StorePathHash {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
+pub struct StorePathName(String);
+
+impl StorePathName {
+    pub fn new(s: &str) -> Result<Self, Error> {
+        if s.len() == 0 {
+            return Err(Error::StorePathNameEmpty);
+        }
+
+        if s.len() > 211 {
+            return Err(Error::StorePathNameTooLong);
+        }
+
+        if s.starts_with('.')
+            || !s.chars().all(|c| {
+                c.is_ascii_alphabetic()
+                    || c.is_ascii_digit()
+                    || c == '+'
+                    || c == '-'
+                    || c == '.'
+                    || c == '_'
+                    || c == '?'
+                    || c == '='
+            })
+        {
+            return Err(Error::BadStorePathName);
+        }
+
+        Ok(Self(s.to_string()))
+    }
+
+    pub fn name<'a>(&'a self) -> &'a str {
+        &self.0
+    }
+}
+
+impl fmt::Display for StorePathName {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.0)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use assert_matches::assert_matches;
+
+    #[test]
+    fn test_parse() {
+        let s = "7h7qgvs4kgzsn8a6rb273saxyqh4jxlz-konsole-18.12.3";
+        let p = StorePath::new_from_base_name(&s).unwrap();
+        assert_eq!(p.name.0, "konsole-18.12.3");
+        assert_eq!(
+            p.hash.0,
+            [
+                0x9f, 0x76, 0x49, 0x20, 0xf6, 0x5d, 0xe9, 0x71, 0xc4, 0xca, 0x46, 0x21, 0xab, 0xff,
+                0x9b, 0x44, 0xef, 0x87, 0x0f, 0x3c
+            ]
+        );
+    }
+
+    #[test]
+    fn test_no_name() {
+        let s = "7h7qgvs4kgzsn8a6rb273saxyqh4jxlz-";
+        assert_matches!(
+            StorePath::new_from_base_name(&s),
+            Err(Error::StorePathNameEmpty)
+        );
+    }
+
+    #[test]
+    fn test_no_dash() {
+        let s = "7h7qgvs4kgzsn8a6rb273saxyqh4jxlz";
+        assert_matches!(
+            StorePath::new_from_base_name(&s),
+            Err(Error::BadStorePath(_))
+        );
+    }
+
+    #[test]
+    fn test_short_hash() {
+        let s = "7h7qgvs4kgzsn8a6rb273saxyqh4jxl-konsole-18.12.3";
+        assert_matches!(
+            StorePath::new_from_base_name(&s),
+            Err(Error::BadStorePath(_))
+        );
+    }
+
+    #[test]
+    fn test_invalid_hash() {
+        let s = "7h7qgvs4kgzsn8e6rb273saxyqh4jxlz-konsole-18.12.3";
+        assert_matches!(StorePath::new_from_base_name(&s), Err(Error::BadBase32));
+    }
+
+    #[test]
+    fn test_long_name() {
+        let s = "7h7qgvs4kgzsn8a6rb273saxyqh4jxlz-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
+        assert_matches!(StorePath::new_from_base_name(&s), Ok(_));
+    }
+
+    #[test]
+    fn test_too_long_name() {
+        let s = "7h7qgvs4kgzsn8a6rb273saxyqh4jxlz-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
+        assert_matches!(
+            StorePath::new_from_base_name(&s),
+            Err(Error::StorePathNameTooLong)
+        );
+    }
+
+    #[test]
+    fn test_bad_name() {
+        let s = "7h7qgvs4kgzsn8a6rb273saxyqh4jxlz-foo bar";
+        assert_matches!(
+            StorePath::new_from_base_name(&s),
+            Err(Error::BadStorePathName)
+        );
+
+        let s = "7h7qgvs4kgzsn8a6rb273saxyqh4jxlz-kónsole";
+        assert_matches!(
+            StorePath::new_from_base_name(&s),
+            Err(Error::BadStorePathName)
+        );
+    }
+
+    #[test]
+    fn test_roundtrip() {
+        let s = "7h7qgvs4kgzsn8a6rb273saxyqh4jxlz-konsole-18.12.3";
+        assert_eq!(StorePath::new_from_base_name(&s).unwrap().to_string(), s);
+    }
+}

nix-rust/src/store/path_info.rs

@@ -0,0 +1,70 @@
+use crate::store::StorePath;
+use crate::Error;
+use std::collections::BTreeSet;
+
+#[derive(Clone, Debug)]
+pub struct PathInfo {
+    pub path: StorePath,
+    pub references: BTreeSet<StorePath>,
+    pub nar_size: u64,
+    pub deriver: Option<StorePath>,
+
+    // Additional binary cache info.
+    pub url: Option<String>,
+    pub compression: Option<String>,
+    pub file_size: Option<u64>,
+}
+
+impl PathInfo {
+    pub fn parse_nar_info(nar_info: &str, store_dir: &str) -> Result<Self, Error> {
+        let mut path = None;
+        let mut references = BTreeSet::new();
+        let mut nar_size = None;
+        let mut deriver = None;
+        let mut url = None;
+        let mut compression = None;
+        let mut file_size = None;
+
+        for line in nar_info.lines() {
+            let colon = line.find(':').ok_or(Error::BadNarInfo)?;
+
+            let (name, value) = line.split_at(colon);
+
+            if !value.starts_with(": ") {
+                return Err(Error::BadNarInfo);
+            }
+
+            let value = &value[2..];
+
+            if name == "StorePath" {
+                path = Some(StorePath::new(std::path::Path::new(value), store_dir)?);
+            } else if name == "NarSize" {
+                nar_size = Some(u64::from_str_radix(value, 10).map_err(|_| Error::BadNarInfo)?);
+            } else if name == "References" {
+                if !value.is_empty() {
+                    for r in value.split(' ') {
+                        references.insert(StorePath::new_from_base_name(r)?);
+                    }
+                }
+            } else if name == "Deriver" {
+                deriver = Some(StorePath::new_from_base_name(value)?);
+            } else if name == "URL" {
+                url = Some(value.into());
+            } else if name == "Compression" {
+                compression = Some(value.into());
+            } else if name == "FileSize" {
+                file_size = Some(u64::from_str_radix(value, 10).map_err(|_| Error::BadNarInfo)?);
+            }
+        }
+
+        Ok(PathInfo {
+            path: path.ok_or(Error::BadNarInfo)?,
+            references,
+            nar_size: nar_size.ok_or(Error::BadNarInfo)?,
+            deriver,
+            url: Some(url.ok_or(Error::BadNarInfo)?),
+            compression,
+            file_size,
+        })
+    }
+}

nix-rust/src/store/store.rs

@@ -0,0 +1,53 @@
+use super::{PathInfo, StorePath};
+use crate::Error;
+use std::collections::{BTreeMap, BTreeSet};
+use std::path::Path;
+
+pub trait Store: Send + Sync {
+    fn store_dir(&self) -> &str {
+        "/nix/store"
+    }
+
+    fn query_path_info(
+        &self,
+        store_path: &StorePath,
+    ) -> std::pin::Pin<Box<dyn std::future::Future<Output = Result<PathInfo, Error>> + Send>>;
+}
+
+impl dyn Store {
+    pub fn parse_store_path(&self, path: &Path) -> Result<StorePath, Error> {
+        StorePath::new(path, self.store_dir())
+    }
+
+    pub async fn compute_path_closure(
+        &self,
+        roots: BTreeSet<StorePath>,
+    ) -> Result<BTreeMap<StorePath, PathInfo>, Error> {
+        let mut done = BTreeSet::new();
+        let mut result = BTreeMap::new();
+        let mut pending = vec![];
+
+        for root in roots {
+            pending.push(self.query_path_info(&root));
+            done.insert(root);
+        }
+
+        while !pending.is_empty() {
+            let (info, _, remaining) = futures::future::select_all(pending).await;
+            pending = remaining;
+
+            let info = info?;
+
+            for path in &info.references {
+                if !done.contains(path) {
+                    pending.push(self.query_path_info(&path));
+                    done.insert(path.clone());
+                }
+            }
+
+            result.insert(info.path.clone(), info);
+        }
+
+        Ok(result)
+    }
+}

nix-rust/src/util/base32.rs

@@ -0,0 +1,160 @@
+use crate::error::Error;
+use lazy_static::lazy_static;
+
+pub fn encoded_len(input_len: usize) -> usize {
+    if input_len == 0 {
+        0
+    } else {
+        (input_len * 8 - 1) / 5 + 1
+    }
+}
+
+pub fn decoded_len(input_len: usize) -> usize {
+    input_len * 5 / 8
+}
+
+static BASE32_CHARS: &'static [u8; 32] = &b"0123456789abcdfghijklmnpqrsvwxyz";
+
+lazy_static! {
+    static ref BASE32_CHARS_REVERSE: Box<[u8; 256]> = {
+        let mut xs = [0xffu8; 256];
+        for (n, c) in BASE32_CHARS.iter().enumerate() {
+            xs[*c as usize] = n as u8;
+        }
+        Box::new(xs)
+    };
+}
+
+pub fn encode(input: &[u8]) -> String {
+    let mut buf = vec![0; encoded_len(input.len())];
+    encode_into(input, &mut buf);
+    std::str::from_utf8(&buf).unwrap().to_string()
+}
+
+pub fn encode_into(input: &[u8], output: &mut [u8]) {
+    let len = encoded_len(input.len());
+    assert_eq!(len, output.len());
+
+    let mut nr_bits_left: usize = 0;
+    let mut bits_left: u16 = 0;
+    let mut pos = len;
+
+    for b in input {
+        bits_left |= (*b as u16) << nr_bits_left;
+        nr_bits_left += 8;
+        while nr_bits_left > 5 {
+            output[pos - 1] = BASE32_CHARS[(bits_left & 0x1f) as usize];
+            pos -= 1;
+            bits_left >>= 5;
+            nr_bits_left -= 5;
+        }
+    }
+
+    if nr_bits_left > 0 {
+        output[pos - 1] = BASE32_CHARS[(bits_left & 0x1f) as usize];
+        pos -= 1;
+    }
+
+    assert_eq!(pos, 0);
+}
+
+pub fn decode(input: &str) -> Result<Vec<u8>, crate::Error> {
+    let mut res = Vec::with_capacity(decoded_len(input.len()));
+
+    let mut nr_bits_left: usize = 0;
+    let mut bits_left: u16 = 0;
+
+    for c in input.chars().rev() {
+        let b = BASE32_CHARS_REVERSE[c as usize];
+        if b == 0xff {
+            return Err(Error::BadBase32);
+        }
+        bits_left |= (b as u16) << nr_bits_left;
+        nr_bits_left += 5;
+        if nr_bits_left >= 8 {
+            res.push((bits_left & 0xff) as u8);
+            bits_left >>= 8;
+            nr_bits_left -= 8;
+        }
+    }
+
+    if nr_bits_left > 0 && bits_left != 0 {
+        return Err(Error::BadBase32);
+    }
+
+    Ok(res)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use assert_matches::assert_matches;
+    use hex;
+    use proptest::proptest;
+
+    #[test]
+    fn test_encode() {
+        assert_eq!(encode(&[]), "");
+
+        assert_eq!(
+            encode(&hex::decode("0839703786356bca59b0f4a32987eb2e6de43ae8").unwrap()),
+            "x0xf8v9fxf3jk8zln1cwlsrmhqvp0f88"
+        );
+
+        assert_eq!(
+            encode(
+                &hex::decode("ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad")
+                    .unwrap()
+            ),
+            "1b8m03r63zqhnjf7l5wnldhh7c134ap5vpj0850ymkq1iyzicy5s"
+        );
+
+        assert_eq!(
+            encode(
+                &hex::decode("ddaf35a193617abacc417349ae20413112e6fa4e89a97ea20a9eeee64b55d39a2192992a274fc1a836ba3c23a3feebbd454d4423643ce80e2a9ac94fa54ca49f")
+                    .unwrap()
+            ),
+            "2gs8k559z4rlahfx0y688s49m2vvszylcikrfinm30ly9rak69236nkam5ydvly1ai7xac99vxfc4ii84hawjbk876blyk1jfhkbbyx"
+        );
+    }
+
+    #[test]
+    fn test_decode() {
+        assert_eq!(hex::encode(decode("").unwrap()), "");
+
+        assert_eq!(
+            hex::encode(decode("x0xf8v9fxf3jk8zln1cwlsrmhqvp0f88").unwrap()),
+            "0839703786356bca59b0f4a32987eb2e6de43ae8"
+        );
+
+        assert_eq!(
+            hex::encode(decode("1b8m03r63zqhnjf7l5wnldhh7c134ap5vpj0850ymkq1iyzicy5s").unwrap()),
+            "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"
+        );
+
+        assert_eq!(
+            hex::encode(decode("2gs8k559z4rlahfx0y688s49m2vvszylcikrfinm30ly9rak69236nkam5ydvly1ai7xac99vxfc4ii84hawjbk876blyk1jfhkbbyx").unwrap()),
+            "ddaf35a193617abacc417349ae20413112e6fa4e89a97ea20a9eeee64b55d39a2192992a274fc1a836ba3c23a3feebbd454d4423643ce80e2a9ac94fa54ca49f"
+        );
+
+        assert_matches!(
+            decode("xoxf8v9fxf3jk8zln1cwlsrmhqvp0f88"),
+            Err(Error::BadBase32)
+        );
+        assert_matches!(
+            decode("2b8m03r63zqhnjf7l5wnldhh7c134ap5vpj0850ymkq1iyzicy5s"),
+            Err(Error::BadBase32)
+        );
+        assert_matches!(decode("2"), Err(Error::BadBase32));
+        assert_matches!(decode("2gs"), Err(Error::BadBase32));
+        assert_matches!(decode("2gs8"), Err(Error::BadBase32));
+    }
+
+    proptest! {
+
+        #[test]
+        fn roundtrip(s: Vec<u8>) {
+            assert_eq!(s, decode(&encode(&s)).unwrap());
+        }
+    }
+}

nix-rust/src/util/mod.rs

@@ -0,0 +1 @@
+pub mod base32;

nix.spec.in

@@ -1,173 +0,0 @@
-%undefine _hardened_build
-
-%global nixbld_user "nix-builder-"
-%global nixbld_group "nixbld"
-
-# NOTE: BUILD on EL7 requires
-# - Centos / RHEL7 software collection repository 
-#   yum install centos-release-scl
-#
-# - Recent boost backport
-#   curl https://copr.fedorainfracloud.org/coprs/whosthere/boost/repo/epel-7/whosthere-boost-epel-7.repo -o /etc/yum.repos.d/whosthere-boost-epel-7.repo
-#
-
-# Disable documentation generation
-# necessary on some platforms
-%bcond_without docgen
-
-Summary: The Nix software deployment system
-Name: nix
-Version: @PACKAGE_VERSION@
-Release: 2%{?dist}
-License: LGPLv2+
-Group: Applications/System
-URL: http://nixos.org/
-Source0: %{name}-%{version}.tar.bz2
-
-Requires: curl
-Requires: bzip2
-Requires: gzip
-Requires: xz
-BuildRequires: bison
-BuildRequires: boost-devel >= 1.60
-BuildRequires: bzip2-devel
-
-# for RHEL <= 7, we need software collections for a C++14 compatible compatible compiler
-%if 0%{?rhel}
-BuildRequires: devtoolset-7-gcc
-BuildRequires: devtoolset-7-gcc-c++
-%endif
-
-BuildRequires: flex
-BuildRequires: libcurl-devel
-BuildRequires: libseccomp-devel
-BuildRequires: openssl-devel
-BuildRequires: sqlite-devel
-BuildRequires: xz-devel
-
-%description
-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.
-
-%package        devel
-Summary:        Development files for %{name}
-Requires:       %{name}%{?_isa} = %{version}-%{release}
-
-%description   devel
-The %{name}-devel package contains libraries and header files for
-developing applications that use %{name}.
-
-
-%package doc
-Summary:        Documentation files for %{name}
-BuildArch:      noarch
-Requires:       %{name} = %{version}-%{release}
-
-%description   doc
-The %{name}-doc package contains documentation files for %{name}.
-
-%prep
-%setup -q
-
-
-%build
-%if 0%{?rhel}
-source /opt/rh/devtoolset-7/enable 
-%endif
-extraFlags=
-# - override docdir so large documentation files are owned by the
-#   -doc subpackage
-# - set localstatedir by hand to the preferred nix value
-%configure --localstatedir=/nix/var \
-	   %{!?without_docgen:--disable-doc-gen} \
-           --docdir=%{_defaultdocdir}/%{name}-doc-%{version} \
-           $extraFlags
-make V=1 %{?_smp_mflags}
-
-
-%install
-%if 0%{?rhel}
-source /opt/rh/devtoolset-7/enable 
-%endif
-
-make DESTDIR=$RPM_BUILD_ROOT install
-
-find $RPM_BUILD_ROOT -name '*.la' -exec rm -f {} ';'
-
-# make the store
-mkdir -p $RPM_BUILD_ROOT/nix/store
-chmod 1775 $RPM_BUILD_ROOT/nix/store
-
-# make per-user directories
-for d in profiles gcroots;
-do
-  mkdir -p $RPM_BUILD_ROOT/nix/var/nix/$d/per-user
-  chmod 1777 $RPM_BUILD_ROOT/nix/var/nix/$d/per-user
-done
-
-# fix permission of nix profile
-# (until this is fixed in the relevant Makefile)
-chmod -x $RPM_BUILD_ROOT%{_sysconfdir}/profile.d/nix.sh
-
-# we ship this file in the base package
-rm -f $RPM_BUILD_ROOT%{_defaultdocdir}/%{name}-doc-%{version}/README
-
-# Get rid of Upstart job.
-rm -rf $RPM_BUILD_ROOT%{_sysconfdir}/init
-
-
-%clean
-rm -rf $RPM_BUILD_ROOT
-
-
-%pre
-getent group %{nixbld_group} >/dev/null || groupadd -r %{nixbld_group}
-for i in $(seq 10);
-do
-  getent passwd %{nixbld_user}$i >/dev/null || \
-    useradd -r -g %{nixbld_group} -G %{nixbld_group} -d /var/empty \
-      -s %{_sbindir}/nologin \
-      -c "Nix build user $i" %{nixbld_user}$i
-done
-
-%post
-chgrp %{nixbld_group} /nix/store
-%if ! 0%{?rhel} || 0%{?rhel} >= 7
-# Enable and start Nix worker
-systemctl enable nix-daemon.socket nix-daemon.service
-systemctl start  nix-daemon.socket
-%endif
-
-%files
-%license COPYING
-%{_bindir}/nix*
-%{_libdir}/*.so
-%{_prefix}/libexec/*
-%if ! 0%{?rhel} || 0%{?rhel} >= 7
-%{_prefix}/lib/systemd/system/nix-daemon.socket
-%{_prefix}/lib/systemd/system/nix-daemon.service
-%endif
-%{_datadir}/nix
-#%if ! %{without docgen}
-#%{_mandir}/man1/*.1*
-#%{_mandir}/man5/*.5*
-#%{_mandir}/man8/*.8*
-#%endif
-%config(noreplace) %{_sysconfdir}/profile.d/nix.sh
-%config(noreplace) %{_sysconfdir}/profile.d/nix-daemon.sh
-/nix
-
-%files devel
-%{_includedir}/nix
-%{_prefix}/lib/pkgconfig/*.pc
-
-
-#%if ! %{without docgen}
-#%files doc
-#%docdir %{_defaultdocdir}/%{name}-doc-%{version}
-#%{_defaultdocdir}/%{name}-doc-%{version}
-#%endif

perl/Makefile

@@ -7,8 +7,9 @@ GLOBAL_CXXFLAGS += -g -Wall
 OPTIMIZE = 1
 
 ifeq ($(OPTIMIZE), 1)
-  GLOBAL_CFLAGS += -O3
   GLOBAL_CXXFLAGS += -O3
+else
+  GLOBAL_CXXFLAGS += -O0
 endif
 
 include mk/lib.mk

perl/configure.ac

@@ -6,7 +6,6 @@ CFLAGS=
 CXXFLAGS=
 AC_PROG_CC
 AC_PROG_CXX
-AX_CXX_COMPILE_STDCXX_11
 
 # Use 64-bit file system calls so that we can support files > 2 GiB.
 AC_SYS_LARGEFILE
@@ -69,14 +68,15 @@ AC_SUBST(perlFlags)
 
 PKG_CHECK_MODULES([NIX], [nix-store])
 
-NEED_PROG([NIX_INSTANTIATE_PROGRAM], [nix-instantiate])
+NEED_PROG([NIX], [nix])
 
 # Get nix configure values
-nixbindir=$("$NIX_INSTANTIATE_PROGRAM" --eval '<nix/config.nix>' -A nixBinDir | tr -d \")
-nixlibexecdir=$("$NIX_INSTANTIATE_PROGRAM" --eval '<nix/config.nix>' -A nixLibexecDir | tr -d \")
-nixlocalstatedir=$("$NIX_INSTANTIATE_PROGRAM" --eval '<nix/config.nix>' -A nixLocalstateDir | tr -d \")
-nixsysconfdir=$("$NIX_INSTANTIATE_PROGRAM" --eval '<nix/config.nix>' -A nixSysconfDir | tr -d \")
-nixstoredir=$("$NIX_INSTANTIATE_PROGRAM" --eval '<nix/config.nix>' -A nixStoreDir | tr -d \")
+export NIX_REMOTE=daemon
+nixbindir=$("$NIX" --experimental-features nix-command eval --raw -f '<nix/config.nix>' nixBinDir)
+nixlibexecdir=$("$NIX" --experimental-features nix-command eval --raw -f '<nix/config.nix>' nixLibexecDir)
+nixlocalstatedir=$("$NIX" --experimental-features nix-command eval --raw -f '<nix/config.nix>' nixLocalstateDir)
+nixsysconfdir=$("$NIX" --experimental-features nix-command eval --raw -f '<nix/config.nix>' nixSysconfDir)
+nixstoredir=$("$NIX" --experimental-features nix-command eval --raw -f '<nix/config.nix>' nixStoreDir)
 AC_SUBST(nixbindir)
 AC_SUBST(nixlibexecdir)
 AC_SUBST(nixlocalstatedir)

perl/lib/Nix/Config.pm.in

@@ -11,10 +11,6 @@ $logDir = $ENV{"NIX_LOG_DIR"} || "@nixlocalstatedir@/log/nix";
 $confDir = $ENV{"NIX_CONF_DIR"} || "@nixsysconfdir@/nix";
 $storeDir = $ENV{"NIX_STORE_DIR"} || "@nixstoredir@";
 
-$bzip2 = "@bzip2@";
-$xz = "@xz@";
-$curl = "@curl@";
-
 $useBindings = 1;
 
 %config = ();

perl/lib/Nix/Store.xs

@@ -59,7 +59,7 @@ void setVerbosity(int level)
 int isValidPath(char * path)
     CODE:
         try {
-            RETVAL = store()->isValidPath(path);
+            RETVAL = store()->isValidPath(store()->parseStorePath(path));
         } catch (Error & e) {
             croak("%s", e.what());
         }
@@ -70,9 +70,8 @@ int isValidPath(char * path)
 SV * queryReferences(char * path)
     PPCODE:
         try {
-            PathSet paths = store()->queryPathInfo(path)->references;
-            for (PathSet::iterator i = paths.begin(); i != paths.end(); ++i)
-                XPUSHs(sv_2mortal(newSVpv(i->c_str(), 0)));
+            for (auto & i : store()->queryPathInfo(store()->parseStorePath(path))->references)
+                XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(i).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
         }
@@ -81,7 +80,7 @@ SV * queryReferences(char * path)
 SV * queryPathHash(char * path)
     PPCODE:
         try {
-            auto s = store()->queryPathInfo(path)->narHash.to_string();
+            auto s = store()->queryPathInfo(store()->parseStorePath(path))->narHash.to_string();
             XPUSHs(sv_2mortal(newSVpv(s.c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
@@ -91,9 +90,9 @@ SV * queryPathHash(char * path)
 SV * queryDeriver(char * path)
     PPCODE:
         try {
-            auto deriver = store()->queryPathInfo(path)->deriver;
-            if (deriver == "") XSRETURN_UNDEF;
-            XPUSHs(sv_2mortal(newSVpv(deriver.c_str(), 0)));
+            auto info = store()->queryPathInfo(store()->parseStorePath(path));
+            if (!info->deriver) XSRETURN_UNDEF;
+            XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(*info->deriver).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
         }
@@ -102,18 +101,18 @@ SV * queryDeriver(char * path)
 SV * queryPathInfo(char * path, int base32)
     PPCODE:
         try {
-            auto info = store()->queryPathInfo(path);
-            if (info->deriver == "")
+            auto info = store()->queryPathInfo(store()->parseStorePath(path));
+            if (!info->deriver)
                 XPUSHs(&PL_sv_undef);
             else
-                XPUSHs(sv_2mortal(newSVpv(info->deriver.c_str(), 0)));
+                XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(*info->deriver).c_str(), 0)));
             auto s = info->narHash.to_string(base32 ? Base32 : Base16);
             XPUSHs(sv_2mortal(newSVpv(s.c_str(), 0)));
             mXPUSHi(info->registrationTime);
             mXPUSHi(info->narSize);
             AV * arr = newAV();
-            for (PathSet::iterator i = info->references.begin(); i != info->references.end(); ++i)
-                av_push(arr, newSVpv(i->c_str(), 0));
+            for (auto & i : info->references)
+                av_push(arr, newSVpv(store()->printStorePath(i).c_str(), 0));
             XPUSHs(sv_2mortal(newRV((SV *) arr)));
         } catch (Error & e) {
             croak("%s", e.what());
@@ -123,8 +122,8 @@ SV * queryPathInfo(char * path, int base32)
 SV * queryPathFromHashPart(char * hashPart)
     PPCODE:
         try {
-            Path path = store()->queryPathFromHashPart(hashPart);
-            XPUSHs(sv_2mortal(newSVpv(path.c_str(), 0)));
+            auto path = store()->queryPathFromHashPart(hashPart);
+            XPUSHs(sv_2mortal(newSVpv(path ? store()->printStorePath(*path).c_str() : "", 0)));
         } catch (Error & e) {
             croak("%s", e.what());
         }
@@ -133,11 +132,11 @@ SV * queryPathFromHashPart(char * hashPart)
 SV * computeFSClosure(int flipDirection, int includeOutputs, ...)
     PPCODE:
         try {
-            PathSet paths;
+            StorePathSet paths;
             for (int n = 2; n < items; ++n)
-                store()->computeFSClosure(SvPV_nolen(ST(n)), paths, flipDirection, includeOutputs);
-            for (PathSet::iterator i = paths.begin(); i != paths.end(); ++i)
-                XPUSHs(sv_2mortal(newSVpv(i->c_str(), 0)));
+                store()->computeFSClosure(store()->parseStorePath(SvPV_nolen(ST(n))), paths, flipDirection, includeOutputs);
+            for (auto & i : paths)
+                XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(i).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
         }
@@ -146,11 +145,11 @@ SV * computeFSClosure(int flipDirection, int includeOutputs, ...)
 SV * topoSortPaths(...)
     PPCODE:
         try {
-            PathSet paths;
-            for (int n = 0; n < items; ++n) paths.insert(SvPV_nolen(ST(n)));
-            Paths sorted = store()->topoSortPaths(paths);
-            for (Paths::iterator i = sorted.begin(); i != sorted.end(); ++i)
-                XPUSHs(sv_2mortal(newSVpv(i->c_str(), 0)));
+            StorePathSet paths;
+            for (int n = 0; n < items; ++n) paths.insert(store()->parseStorePath(SvPV_nolen(ST(n))));
+            auto sorted = store()->topoSortPaths(paths);
+            for (auto & i : sorted)
+                XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(i).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
         }
@@ -159,7 +158,7 @@ SV * topoSortPaths(...)
 SV * followLinksToStorePath(char * path)
     CODE:
         try {
-            RETVAL = newSVpv(store()->followLinksToStorePath(path).c_str(), 0);
+            RETVAL = newSVpv(store()->printStorePath(store()->followLinksToStorePath(path)).c_str(), 0);
         } catch (Error & e) {
             croak("%s", e.what());
         }
@@ -170,8 +169,8 @@ SV * followLinksToStorePath(char * path)
 void exportPaths(int fd, ...)
     PPCODE:
         try {
-            Paths paths;
-            for (int n = 1; n < items; ++n) paths.push_back(SvPV_nolen(ST(n)));
+            StorePathSet paths;
+            for (int n = 1; n < items; ++n) paths.insert(store()->parseStorePath(SvPV_nolen(ST(n))));
             FdSink sink(fd);
             store()->exportPaths(paths, sink);
         } catch (Error & e) {
@@ -275,8 +274,8 @@ int checkSignature(SV * publicKey_, SV * sig_, char * msg)
 SV * addToStore(char * srcPath, int recursive, char * algo)
     PPCODE:
         try {
-            Path path = store()->addToStore(baseNameOf(srcPath), srcPath, recursive, parseHashType(algo));
-            XPUSHs(sv_2mortal(newSVpv(path.c_str(), 0)));
+            auto path = store()->addToStore(std::string(baseNameOf(srcPath)), srcPath, recursive, parseHashType(algo));
+            XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(path).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
         }
@@ -286,8 +285,8 @@ SV * makeFixedOutputPath(int recursive, char * algo, char * hash, char * name)
     PPCODE:
         try {
             Hash h(hash, parseHashType(algo));
-            Path path = store()->makeFixedOutputPath(recursive, h, name);
-            XPUSHs(sv_2mortal(newSVpv(path.c_str(), 0)));
+            auto path = store()->makeFixedOutputPath(recursive, h, name);
+            XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(path).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
         }
@@ -298,35 +297,35 @@ SV * derivationFromPath(char * drvPath)
         HV *hash;
     CODE:
         try {
-            Derivation drv = store()->derivationFromPath(drvPath);
+            Derivation drv = store()->derivationFromPath(store()->parseStorePath(drvPath));
             hash = newHV();
 
             HV * outputs = newHV();
-            for (DerivationOutputs::iterator i = drv.outputs.begin(); i != drv.outputs.end(); ++i)
-                hv_store(outputs, i->first.c_str(), i->first.size(), newSVpv(i->second.path.c_str(), 0), 0);
+            for (auto & i : drv.outputs)
+                hv_store(outputs, i.first.c_str(), i.first.size(), newSVpv(store()->printStorePath(i.second.path).c_str(), 0), 0);
             hv_stores(hash, "outputs", newRV((SV *) outputs));
 
             AV * inputDrvs = newAV();
-            for (DerivationInputs::iterator i = drv.inputDrvs.begin(); i != drv.inputDrvs.end(); ++i)
-                av_push(inputDrvs, newSVpv(i->first.c_str(), 0)); // !!! ignores i->second
+            for (auto & i : drv.inputDrvs)
+                av_push(inputDrvs, newSVpv(store()->printStorePath(i.first).c_str(), 0)); // !!! ignores i->second
             hv_stores(hash, "inputDrvs", newRV((SV *) inputDrvs));
 
             AV * inputSrcs = newAV();
-            for (PathSet::iterator i = drv.inputSrcs.begin(); i != drv.inputSrcs.end(); ++i)
-                av_push(inputSrcs, newSVpv(i->c_str(), 0));
+            for (auto & i : drv.inputSrcs)
+                av_push(inputSrcs, newSVpv(store()->printStorePath(i).c_str(), 0));
             hv_stores(hash, "inputSrcs", newRV((SV *) inputSrcs));
 
             hv_stores(hash, "platform", newSVpv(drv.platform.c_str(), 0));
             hv_stores(hash, "builder", newSVpv(drv.builder.c_str(), 0));
 
             AV * args = newAV();
-            for (Strings::iterator i = drv.args.begin(); i != drv.args.end(); ++i)
-                av_push(args, newSVpv(i->c_str(), 0));
+            for (auto & i : drv.args)
+                av_push(args, newSVpv(i.c_str(), 0));
             hv_stores(hash, "args", newRV((SV *) args));
 
             HV * env = newHV();
-            for (StringPairs::iterator i = drv.env.begin(); i != drv.env.end(); ++i)
-                hv_store(env, i->first.c_str(), i->first.size(), newSVpv(i->second.c_str(), 0), 0);
+            for (auto & i : drv.env)
+                hv_store(env, i.first.c_str(), i.first.size(), newSVpv(i.second.c_str(), 0), 0);
             hv_stores(hash, "env", newRV((SV *) env));
 
             RETVAL = newRV_noinc((SV *)hash);
@@ -340,7 +339,7 @@ SV * derivationFromPath(char * drvPath)
 void addTempRoot(char * storePath)
     PPCODE:
         try {
-            store()->addTempRoot(storePath);
+            store()->addTempRoot(store()->parseStorePath(storePath));
         } catch (Error & e) {
             croak("%s", e.what());
         }

precompiled-headers.h

@@ -0,0 +1,61 @@
+#include <algorithm>
+#include <array>
+#include <atomic>
+#include <cassert>
+#include <cctype>
+#include <chrono>
+#include <climits>
+#include <cmath>
+#include <condition_variable>
+#include <cstddef>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <exception>
+#include <functional>
+#include <future>
+#include <iostream>
+#include <limits>
+#include <list>
+#include <locale>
+#include <map>
+#include <memory>
+#include <mutex>
+#include <numeric>
+#include <optional>
+#include <queue>
+#include <random>
+#include <regex>
+#include <set>
+#include <sstream>
+#include <stack>
+#include <stdexcept>
+#include <string>
+#include <thread>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include <boost/format.hpp>
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <netdb.h>
+#include <pwd.h>
+#include <signal.h>
+#include <sys/resource.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/utsname.h>
+#include <sys/wait.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "util.hh"
+#include "args.hh"

release-common.nix

@@ -30,28 +30,27 @@ rec {
   });
 
   configureFlags =
-    [
-      "--enable-gc"
-    ] ++ lib.optionals stdenv.isLinux [
+    lib.optionals stdenv.isLinux [
       "--with-sandbox-shell=${sh}/bin/busybox"
     ];
 
-  tarballDeps =
+  buildDeps =
     [ bison
       flex
       libxml2
       libxslt
       docbook5
-      docbook5_xsl
+      docbook_xsl_ns
       autoconf-archive
       autoreconfHook
-    ];
 
-  buildDeps =
-    [ curl
-      bzip2 xz brotli editline
-      openssl pkgconfig sqlite boehmgc
+      curl
+      bzip2 xz brotli zlib editline
+      openssl pkgconfig sqlite
+      libarchive
       boost
+      nlohmann_json
+      rustc cargo
 
       # Tests
       git
@@ -72,6 +71,10 @@ rec {
         */
       }));
 
+  propagatedDeps =
+    [ (boehmgc.override { enableLargeConfig = true; })
+    ];
+
   perlDeps =
     [ perl
       perlPackages.DBDSQLite

release.nix

@@ -1,5 +1,5 @@
 { nix ? builtins.fetchGit ./.
-, nixpkgs ? builtins.fetchGit { url = https://github.com/NixOS/nixpkgs-channels.git; ref = "nixos-19.03"; }
+, nixpkgs ? builtins.fetchTarball https://github.com/NixOS/nixpkgs/archive/nixos-20.03-small.tar.gz
 , officialRelease ? false
 , systems ? [ "x86_64-linux" "i686-linux" "x86_64-darwin" "aarch64-linux" ]
 }:
@@ -8,50 +8,55 @@ let
 
   pkgs = import nixpkgs { system = builtins.currentSystem or "x86_64-linux"; };
 
+  version =
+    builtins.readFile ./.version
+    + (if officialRelease then "" else "pre${toString nix.revCount}_${nix.shortRev}");
+
   jobs = rec {
 
+    # Create a "vendor" directory that contains the crates listed in
+    # Cargo.lock. This allows Nix to be built without network access.
+    vendoredCrates =
+      let
+        lockFile = builtins.fromTOML (builtins.readFile nix-rust/Cargo.lock);
 
-    tarball =
-      with pkgs;
+        files = map (pkg: import <nix/fetchurl.nix> {
+          url = "https://crates.io/api/v1/crates/${pkg.name}/${pkg.version}/download";
+          sha256 = lockFile.metadata."checksum ${pkg.name} ${pkg.version} (registry+https://github.com/rust-lang/crates.io-index)";
+        }) (builtins.filter (pkg: pkg.source or "" == "registry+https://github.com/rust-lang/crates.io-index") lockFile.package);
 
-      with import ./release-common.nix { inherit pkgs; };
+      in pkgs.runCommand "cargo-vendor-dir" {}
+        ''
+          mkdir -p $out/vendor
 
-      releaseTools.sourceTarball {
-        name = "nix-tarball";
-        version = builtins.readFile ./.version;
-        versionSuffix = if officialRelease then "" else "pre${toString nix.revCount}_${nix.shortRev}";
-        src = nix;
-        inherit officialRelease;
+          cat > $out/vendor/config <<EOF
+          [source.crates-io]
+          replace-with = "vendored-sources"
 
-        buildInputs = tarballDeps ++ buildDeps;
+          [source.vendored-sources]
+          directory = "vendor"
+          EOF
 
-        configureFlags = "--enable-gc";
+          ${toString (builtins.map (file: ''
+            mkdir $out/vendor/tmp
+            tar xvf ${file} -C $out/vendor/tmp
+            dir=$(echo $out/vendor/tmp/*)
 
-        postUnpack = ''
-          (cd $sourceRoot && find . -type f) | cut -c3- > $sourceRoot/.dist-files
-          cat $sourceRoot/.dist-files
+            # Add just enough metadata to keep Cargo happy.
+            printf '{"files":{},"package":"${file.outputHash}"}' > "$dir/.cargo-checksum.json"
+
+            # Clean up some cruft from the winapi crates. FIXME: find
+            # a way to remove winapi* from our dependencies.
+            if [[ $dir =~ /winapi ]]; then
+              find $dir -name "*.a" -print0 | xargs -0 rm -f --
+            fi
+
+            mv "$dir" $out/vendor/
+
+            rm -rf $out/vendor/tmp
+          '') files)}
         '';
 
-        preConfigure = ''
-          (cd perl ; autoreconf --install --force --verbose)
-          # TeX needs a writable font cache.
-          export VARTEXFONTS=$TMPDIR/texfonts
-        '';
-
-        distPhase =
-          ''
-            runHook preDist
-            make dist
-            mkdir -p $out/tarballs
-            cp *.tar.* $out/tarballs
-          '';
-
-        preDist = ''
-          make install docdir=$out/share/doc/nix makefiles=doc/manual/local.mk
-          echo "doc manual $out/share/doc/nix/manual" >> $out/nix-support/hydra-build-products
-        '';
-      };
-
 
     build = pkgs.lib.genAttrs systems (system:
 
@@ -61,18 +66,32 @@ let
 
       with import ./release-common.nix { inherit pkgs; };
 
-      releaseTools.nixBuild {
-        name = "nix";
-        src = tarball;
+      stdenv.mkDerivation {
+        name = "nix-${version}";
+
+        src = nix;
+
+        outputs = [ "out" "dev" "doc" ];
 
         buildInputs = buildDeps;
 
+        propagatedBuildInputs = propagatedDeps;
+
         preConfigure =
-          # Copy libboost_context so we don't get all of Boost in our closure.
-          # https://github.com/NixOS/nixpkgs/issues/45462
           ''
+            # Copy libboost_context so we don't get all of Boost in our closure.
+            # https://github.com/NixOS/nixpkgs/issues/45462
             mkdir -p $out/lib
-            cp ${boost}/lib/libboost_context* $out/lib
+            cp -pd ${boost}/lib/{libboost_context*,libboost_thread*,libboost_system*} $out/lib
+            rm -f $out/lib/*.a
+            ${lib.optionalString stdenv.isLinux ''
+              chmod u+w $out/lib/*.so.*
+              patchelf --set-rpath $out/lib:${stdenv.cc.cc.lib}/lib $out/lib/libboost_thread.so.*
+            ''}
+
+            ln -sfn ${vendoredCrates}/vendor/ nix-rust/vendor
+
+            (cd perl; autoreconf --install --force --verbose)
           '';
 
         configureFlags = configureFlags ++
@@ -84,8 +103,17 @@ let
 
         installFlags = "sysconfdir=$(out)/etc";
 
+        doCheck = true;
+
         doInstallCheck = true;
         installCheckFlags = "sysconfdir=$(out)/etc";
+
+        separateDebugInfo = true;
+
+        preDist = ''
+          mkdir -p $doc/nix-support
+          echo "doc manual $doc/share/doc/nix/manual" >> $doc/nix-support/hydra-build-products
+        '';
       });
 
 
@@ -94,11 +122,21 @@ let
       let pkgs = import nixpkgs { inherit system; }; in with pkgs;
 
       releaseTools.nixBuild {
-        name = "nix-perl";
-        src = tarball;
+        name = "nix-perl-${version}";
+
+        src = nix;
 
         buildInputs =
-          [ jobs.build.${system} curl bzip2 xz pkgconfig pkgs.perl boost ]
+          [ autoconf-archive
+            autoreconfHook
+            jobs.build.${system}
+            curl
+            bzip2
+            xz
+            pkgconfig
+            pkgs.perl
+            boost
+          ]
           ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium;
 
         configureFlags = ''
@@ -118,12 +156,11 @@ let
 
       let
         toplevel = builtins.getAttr system jobs.build;
-        version = toplevel.src.version;
         installerClosureInfo = closureInfo { rootPaths = [ toplevel cacert ]; };
       in
 
       runCommand "nix-binary-tarball-${version}"
-        { nativeBuildInputs = lib.optional (system != "aarch64-linux") shellcheck;
+        { #nativeBuildInputs = lib.optional (system != "aarch64-linux") shellcheck;
           meta.description = "Distribution-independent Nix bootstrap binaries for ${system}";
         }
         ''
@@ -165,10 +202,10 @@ let
           chmod +x $TMPDIR/install-systemd-multi-user.sh
           chmod +x $TMPDIR/install-multi-user
           dir=nix-${version}-${system}
-          fn=$out/$dir.tar.bz2
+          fn=$out/$dir.tar.xz
           mkdir -p $out/nix-support
           echo "file binary-dist $fn" >> $out/nix-support/hydra-build-products
-          tar cvfj $fn \
+          tar cvfJ $fn \
             --owner=0 --group=0 --mode=u+rw,uga+r \
             --absolute-names \
             --hard-dereference \
@@ -188,34 +225,30 @@ let
       with import ./release-common.nix { inherit pkgs; };
 
       releaseTools.coverageAnalysis {
-        name = "nix-build";
-        src = tarball;
+        name = "nix-coverage-${version}";
 
-        buildInputs = buildDeps;
+        src = nix;
+
+        enableParallelBuilding = true;
+
+        buildInputs = buildDeps ++ propagatedDeps;
 
         dontInstall = false;
 
         doInstallCheck = true;
 
-        lcovFilter = [ "*/boost/*" "*-tab.*" "*/nlohmann/*" "*/linenoise/*" ];
+        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;
+
+        # To test building without precompiled headers.
+        makeFlagsArray = [ "PRECOMPILE_HEADERS=0" ];
       };
 
 
-    #rpm_fedora27x86_64 = makeRPM_x86_64 (diskImageFunsFun: diskImageFunsFun.fedora27x86_64) [ ];
-
-
-    #deb_debian8i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.debian8i386) [ "libsodium-dev" ] [ "libsodium13" ];
-    #deb_debian8x86_64 = makeDeb_x86_64 (diskImageFunsFun: diskImageFunsFun.debian8x86_64) [ "libsodium-dev" ] [ "libsodium13" ];
-
-    #deb_ubuntu1710i386 = makeDeb_i686 (diskImageFuns: diskImageFuns.ubuntu1710i386) [ ] [ "libsodium18" ];
-    #deb_ubuntu1710x86_64 = makeDeb_x86_64 (diskImageFuns: diskImageFuns.ubuntu1710x86_64) [ ] [ "libsodium18" "libboost-context1.62.0" ];
-
-
     # System tests.
     tests.remoteBuilds = (import ./tests/remote-builds.nix rec {
       inherit nixpkgs;
@@ -257,7 +290,7 @@ let
             x86_64-linux = "${build.x86_64-linux}";
           }
           EOF
-          su - alice -c 'nix upgrade-nix -vvv --nix-store-paths-url file:///tmp/paths.nix'
+          su - alice -c 'nix --experimental-features nix-command upgrade-nix -vvv --nix-store-paths-url file:///tmp/paths.nix'
           (! [ -L /home/alice/.profile-1-link ])
           su - alice -c 'PAGER= nix-store -qR ${build.x86_64-linux}'
 
@@ -266,6 +299,7 @@ let
           umount /nix
         ''); # */
 
+    /*
     tests.evalNixpkgs =
       import (nixpkgs + "/pkgs/top-level/make-tarball.nix") {
         inherit nixpkgs;
@@ -284,101 +318,26 @@ let
 
           touch $out
         '';
+    */
 
 
     installerScript =
       pkgs.runCommand "installer-script"
-        { buildInputs = [ build.x86_64-linux ];
-        }
+        { buildInputs = [ build.${builtins.currentSystem or "x86_64-linux"} ]; }
         ''
           mkdir -p $out/nix-support
 
           substitute ${./scripts/install.in} $out/install \
             ${pkgs.lib.concatMapStrings
-              (system: "--replace '@binaryTarball_${system}@' $(nix hash-file --base16 --type sha256 ${binaryTarball.${system}}/*.tar.bz2) ")
-              [ "x86_64-linux" "i686-linux" "x86_64-darwin" "aarch64-linux" ]
+              (system: "--replace '@binaryTarball_${system}@' $(nix --experimental-features nix-command hash-file --base16 --type sha256 ${binaryTarball.${system}}/*.tar.xz) ")
+              systems
             } \
-            --replace '@nixVersion@' ${build.x86_64-linux.src.version}
+            --replace '@nixVersion@' ${version}
 
           echo "file installer $out/install" >> $out/nix-support/hydra-build-products
         '';
 
-
-    # Aggregate job containing the release-critical jobs.
-    release = pkgs.releaseTools.aggregate {
-      name = "nix-${tarball.version}";
-      meta.description = "Release-critical builds";
-      constituents =
-        [ tarball
-          build.i686-linux
-          build.x86_64-darwin
-          build.x86_64-linux
-          build.aarch64-linux
-          binaryTarball.i686-linux
-          binaryTarball.x86_64-darwin
-          binaryTarball.x86_64-linux
-          binaryTarball.aarch64-linux
-          tests.remoteBuilds
-          tests.nix-copy-closure
-          tests.binaryTarball
-          tests.evalNixpkgs
-          tests.evalNixOS
-          installerScript
-        ];
-    };
-
   };
 
 
-  makeRPM_i686 = makeRPM "i686-linux";
-  makeRPM_x86_64 = makeRPM "x86_64-linux";
-
-  makeRPM =
-    system: diskImageFun: extraPackages:
-
-    with import nixpkgs { inherit system; };
-
-    releaseTools.rpmBuild rec {
-      name = "nix-rpm";
-      src = jobs.tarball;
-      diskImage = (diskImageFun vmTools.diskImageFuns)
-        { extraPackages =
-            [ "sqlite" "sqlite-devel" "bzip2-devel" "libcurl-devel" "openssl-devel" "xz-devel" "libseccomp-devel" "libsodium-devel" "boost-devel" "bison" "flex" ]
-            ++ extraPackages; };
-      # At most 2047MB can be simulated in qemu-system-i386
-      memSize = 2047;
-      meta.schedulingPriority = 50;
-      postRPMInstall = "cd /tmp/rpmout/BUILD/nix-* && make installcheck";
-      #enableParallelBuilding = true;
-    };
-
-
-  makeDeb_i686 = makeDeb "i686-linux";
-  makeDeb_x86_64 = makeDeb "x86_64-linux";
-
-  makeDeb =
-    system: diskImageFun: extraPackages: extraDebPackages:
-
-    with import nixpkgs { inherit system; };
-
-    releaseTools.debBuild {
-      name = "nix-deb";
-      src = jobs.tarball;
-      diskImage = (diskImageFun vmTools.diskImageFuns)
-        { extraPackages =
-            [ "libsqlite3-dev" "libbz2-dev" "libcurl-dev" "libcurl3-nss" "libssl-dev" "liblzma-dev" "libseccomp-dev" "libsodium-dev" "libboost-all-dev" ]
-            ++ extraPackages; };
-      memSize = 2047;
-      meta.schedulingPriority = 50;
-      postInstall = "make installcheck";
-      configureFlags = "--sysconfdir=/etc";
-      debRequires =
-        [ "curl" "libsqlite3-0" "libbz2-1.0" "bzip2" "xz-utils" "libssl1.0.0" "liblzma5" "libseccomp2" ]
-        ++ extraDebPackages;
-      debMaintainer = "Eelco Dolstra <eelco.dolstra@logicblox.com>";
-      doInstallCheck = true;
-      #enableParallelBuilding = true;
-    };
-
-
 in jobs

scripts/install-darwin-multi-user.sh

@@ -39,7 +39,7 @@ EOF
 
 poly_configure_nix_daemon_service() {
     _sudo "to set up the nix-daemon as a LaunchDaemon" \
-          ln -sfn "/nix/var/nix/profiles/default$PLIST_DEST" "$PLIST_DEST"
+          cp -f "/nix/var/nix/profiles/default$PLIST_DEST" "$PLIST_DEST"
 
     _sudo "to load the LaunchDaemon plist for nix-daemon" \
           launchctl load /Library/LaunchDaemons/org.nixos.nix-daemon.plist

scripts/install-multi-user.sh

@@ -13,15 +13,12 @@ set -o pipefail
 # however tracking which bits came from which would be impossible.
 
 readonly ESC='\033[0m'
-readonly BOLD='\033[38;1m'
-readonly BLUE='\033[38;34m'
-readonly BLUE_UL='\033[38;4;34m'
-readonly GREEN='\033[38;32m'
-readonly GREEN_UL='\033[38;4;32m'
-readonly RED='\033[38;31m'
-readonly RED_UL='\033[38;4;31m'
-readonly YELLOW='\033[38;33m'
-readonly YELLOW_UL='\033[38;4;33m'
+readonly BOLD='\033[1m'
+readonly BLUE='\033[34m'
+readonly BLUE_UL='\033[4;34m'
+readonly GREEN='\033[32m'
+readonly GREEN_UL='\033[4;32m'
+readonly RED='\033[31m'
 
 readonly NIX_USER_COUNT="32"
 readonly NIX_BUILD_GROUP_ID="30000"
@@ -240,10 +237,16 @@ EOF
 }
 trap finish_fail EXIT
 
+channel_update_failed=0
 function finish_success {
     finish_cleanup
 
     ok "Alright! We're done!"
+    if [ "x$channel_update_failed" = x1 ]; then
+        echo ""
+        echo "But fetching the nixpkgs channel failed. (Are you offline?)"
+        echo "To try again later, run \"sudo -i nix-channel --update nixpkgs\"."
+    fi
     cat <<EOF
 
 Before Nix will work in your existing shells, you'll need to close
@@ -272,73 +275,9 @@ EOF
     fi
 
     if type nix-env 2> /dev/null >&2; then
-        failure <<EOF
-Nix already appears to be installed, and this tool assumes it is
-_not_ yet installed.
-
-$(uninstall_directions)
-EOF
-    fi
-
-    if [ "${NIX_REMOTE:-}" != "" ]; then
-        failure <<EOF
-For some reason, \$NIX_REMOTE is set. It really should not be set
-before this installer runs, and it hints that Nix is currently
-installed. Please delete the old Nix installation and start again.
-
-Note: You might need to close your shell window and open a new shell
-to clear the variable.
-EOF
-    fi
-
-    if echo "${SSL_CERT_FILE:-}" | grep -qE "(nix/var/nix|nix-profile)"; then
-        failure <<EOF
-It looks like \$SSL_CERT_FILE is set to a path that used to be part of
-the old Nix installation. Please unset that variable and try again:
-
-  $ unset SSL_CERT_FILE
-
-EOF
-    fi
-
-    for file in ~/.bash_profile ~/.bash_login ~/.profile ~/.zshenv ~/.zprofile ~/.zshrc ~/.zlogin; do
-        if [ -f "$file" ]; then
-            if grep -l "^[^#].*.nix-profile" "$file"; then
-                failure <<EOF
-I found a reference to a ".nix-profile" in $file.
-This has a high chance of breaking a new nix installation. It was most
-likely put there by a previous Nix installer.
-
-Please remove this reference and try running this again. You should
-also look for similar references in:
-
- - ~/.bash_profile
- - ~/.bash_login
- - ~/.profile
-
-or other shell init files that you may have.
-
-$(uninstall_directions)
-EOF
-            fi
-        fi
-    done
-
-    if [ -d /nix ]; then
-        failure <<EOF
-There are some relics of a previous installation of Nix at /nix, and
-this scripts assumes Nix is _not_ yet installed. Please delete the old
-Nix installation and start again.
-
-$(uninstall_directions)
-EOF
-    fi
-
-    if [ -d /etc/nix ]; then
-        failure <<EOF
-There are some relics of a previous installation of Nix at /etc/nix, and
-this scripts assumes Nix is _not_ yet installed. Please delete the old
-Nix installation and start again.
+        warning <<EOF
+Nix already appears to be installed. This installer may run into issues.
+If an error occurs, try manually uninstalling, then rerunning this script.
 
 $(uninstall_directions)
 EOF
@@ -346,7 +285,7 @@ EOF
 
     for profile_target in "${PROFILE_TARGETS[@]}"; do
         if [ -e "$profile_target$PROFILE_BACKUP_SUFFIX" ]; then
-        failure <<EOF
+            failure <<EOF
 When this script runs, it backs up the current $profile_target to
 $profile_target$PROFILE_BACKUP_SUFFIX. This backup file already exists, though.
 
@@ -358,38 +297,10 @@ in case.
 2. Take care to make sure that $profile_target$PROFILE_BACKUP_SUFFIX doesn't look like
 it has anything nix-related in it. If it does, something is probably
 quite wrong. Please open an issue or get in touch immediately.
-
-3. Take care to make sure that $profile_target doesn't look like it has
-anything nix-related in it. If it does, and $profile_target _did not_,
-run:
-
-  $ /usr/bin/sudo /bin/mv $profile_target$PROFILE_BACKUP_SUFFIX $profile_target
-
-and try again.
-EOF
-        fi
-
-        if [ -e "$profile_target" ] && grep -qi "nix" "$profile_target"; then
-            failure <<EOF
-It looks like $profile_target already has some Nix configuration in
-there. There should be no reason to run this again. If you're having
-trouble, please open an issue.
 EOF
         fi
     done
 
-    danger_paths=("$ROOT_HOME/.nix-defexpr" "$ROOT_HOME/.nix-channels" "$ROOT_HOME/.nix-profile")
-    for danger_path in "${danger_paths[@]}"; do
-        if _sudo "making sure that $danger_path doesn't exist" \
-           test -e "$danger_path"; then
-            failure <<EOF
-I found a file at $danger_path, which is a relic of a previous
-installation. You must first delete this file before continuing.
-
-$(uninstall_directions)
-EOF
-        fi
-    done
 }
 
 setup_report() {
@@ -523,24 +434,17 @@ create_build_users() {
 }
 
 create_directories() {
+    # FIXME: remove all of this because it duplicates LocalStore::LocalStore().
+
     _sudo "to make the basic directory structure of Nix (part 1)" \
-          mkdir -pv -m 0755 /nix /nix/var /nix/var/log /nix/var/log/nix /nix/var/log/nix/drvs /nix/var/nix{,/db,/gcroots,/profiles,/temproots,/userpool}
+          mkdir -pv -m 0755 /nix /nix/var /nix/var/log /nix/var/log/nix /nix/var/log/nix/drvs /nix/var/nix{,/db,/gcroots,/profiles,/temproots,/userpool} /nix/var/nix/{gcroots,profiles}/per-user
 
     _sudo "to make the basic directory structure of Nix (part 2)" \
-          mkdir -pv -m 1777 /nix/var/nix/{gcroots,profiles}/per-user
-
-    _sudo "to make the basic directory structure of Nix (part 3)" \
           mkdir -pv -m 1775 /nix/store
 
-    _sudo "to make the basic directory structure of Nix (part 4)" \
+    _sudo "to make the basic directory structure of Nix (part 3)" \
           chgrp "$NIX_BUILD_GROUP_NAME" /nix/store
 
-    _sudo "to set up the root user's profile (part 1)" \
-          mkdir -pv -m 0755 /nix/var/nix/profiles/per-user/root
-
-    _sudo "to set up the root user's profile (part 2)" \
-          mkdir -pv -m 0700 "$ROOT_HOME/.nix-defexpr"
-
     _sudo "to place the default nix daemon configuration (part 1)" \
           mkdir -pv -m 0555 /etc/nix
 }
@@ -583,7 +487,7 @@ EOF
 We will:
 
  - make sure your computer doesn't already have Nix files
-   (if it does, I  will tell you how to clean them up.)
+   (if it does, I will tell you how to clean them up.)
  - create local users (see the list above for the users we'll make)
  - create a local group ($NIX_BUILD_GROUP_NAME)
  - install Nix in to $NIX_ROOT
@@ -663,7 +567,7 @@ install_from_extracted_nix() {
         cd "$EXTRACTED_NIX_PATH"
 
         _sudo "to copy the basic Nix files to the new store at $NIX_ROOT/store" \
-              rsync -rlpt ./store/* "$NIX_ROOT/store/"
+              rsync -rlpt --chmod=-w ./store/* "$NIX_ROOT/store/"
 
         if [ -d "$NIX_INSTALLED_NIX" ]; then
             echo "      Alright! We have our first nix at $NIX_INSTALLED_NIX"
@@ -734,16 +638,15 @@ setup_default_profile() {
     # otherwise it will be lost in environments where sudo doesn't pass
     # all the environment variables by default.
     _sudo "to update the default channel in the default profile" \
-          HOME="$ROOT_HOME" NIX_SSL_CERT_FILE="$NIX_SSL_CERT_FILE" "$NIX_INSTALLED_NIX/bin/nix-channel" --update nixpkgs
+          HOME="$ROOT_HOME" NIX_SSL_CERT_FILE="$NIX_SSL_CERT_FILE" "$NIX_INSTALLED_NIX/bin/nix-channel" --update nixpkgs \
+          || channel_update_failed=1
+
 }
 
 
 place_nix_configuration() {
     cat <<EOF > "$SCRATCH/nix.conf"
 build-users-group = $NIX_BUILD_GROUP_NAME
-
-max-jobs = $NIX_USER_COUNT
-cores = 1
 EOF
     _sudo "to place the default nix daemon configuration (part 2)" \
           install -m 0664 "$SCRATCH/nix.conf" /etc/nix/nix.conf
@@ -753,9 +656,13 @@ main() {
     if [ "$(uname -s)" = "Darwin" ]; then
         # shellcheck source=./install-darwin-multi-user.sh
         . "$EXTRACTED_NIX_PATH/install-darwin-multi-user.sh"
-    elif [ "$(uname -s)" = "Linux" ] && [ -e /run/systemd/system ]; then
-        # shellcheck source=./install-systemd-multi-user.sh
-        . "$EXTRACTED_NIX_PATH/install-systemd-multi-user.sh"
+    elif [ "$(uname -s)" = "Linux" ]; then
+        if [ -e /run/systemd/system ]; then
+            # shellcheck source=./install-systemd-multi-user.sh
+            . "$EXTRACTED_NIX_PATH/install-systemd-multi-user.sh"
+        else
+            failure "Sorry, the multi-user installation requires systemd on Linux (detected using /run/systemd/system)"
+        fi
     else
         failure "Sorry, I don't know what to do on $(uname)"
     fi
@@ -763,9 +670,7 @@ main() {
     welcome_to_nix
     chat_about_sudo
 
-    if [ "${ALLOW_PREEXISTING_INSTALLATION:-}" = "" ]; then
-        validate_starting_assumptions
-    fi
+    validate_starting_assumptions
 
     setup_report
 

scripts/install-nix-from-closure.sh

@@ -12,7 +12,7 @@ if ! [ -e "$self/.reginfo" ]; then
     echo "$0: incomplete installer (.reginfo is missing)" >&2
 fi
 
-if [ -z "$USER" ]; then
+if [ -z "$USER" ] && ! USER=$(id -u -n); then
     echo "$0: \$USER is not set" >&2
     exit 1
 fi
@@ -22,10 +22,12 @@ if [ -z "$HOME" ]; then
     exit 1
 fi
 
-# macOS support for 10.10 or higher
+# macOS support for 10.12.6 or higher
 if [ "$(uname -s)" = "Darwin" ]; then
-    if [ $(($(sw_vers -productVersion | cut -d '.' -f 2))) -lt 10 ]; then
-        echo "$0: macOS $(sw_vers -productVersion) is not supported, upgrade to 10.10 or higher"
+    macos_major=$(sw_vers -productVersion | cut -d '.' -f 2)
+    macos_minor=$(sw_vers -productVersion | cut -d '.' -f 3)
+    if [ "$macos_major" -lt 12 ] || { [ "$macos_major" -eq 12 ] && [ "$macos_minor" -lt 6 ]; }; then
+        echo "$0: macOS $(sw_vers -productVersion) is not supported, upgrade to 10.12.6 or higher"
         exit 1
     fi
 fi
@@ -85,7 +87,7 @@ if ! [ -e $dest ]; then
 fi
 
 if ! [ -w $dest ]; then
-    echo "$0: directory $dest exists, but is not writable by you. This could indicate that another user has already performed a single-user installation of Nix on this system. If you wish to enable multi-user support see http://nixos.org/nix/manual/#ssec-multi-user. If you wish to continue with a single-user install for $USER please run 'chown -R $USER $dest' as root." >&2
+    echo "$0: directory $dest exists, but is not writable by you. This could indicate that another user has already performed a single-user installation of Nix on this system. If you wish to enable multi-user support see https://nixos.org/nix/manual/#ssec-multi-user. If you wish to continue with a single-user install for $USER please run 'chown -R $USER $dest' as root." >&2
     exit 1
 fi
 
@@ -100,7 +102,7 @@ for i in $(cd "$self/store" >/dev/null && echo ./*); do
         rm -rf "$i_tmp"
     fi
     if ! [ -e "$dest/store/$i" ]; then
-        cp -Rp "$self/store/$i" "$i_tmp"
+        cp -RPp "$self/store/$i" "$i_tmp"
         chmod -R a-w "$i_tmp"
         chmod +w "$i_tmp"
         mv "$i_tmp" "$dest/store/$i"
@@ -132,15 +134,16 @@ if ! $nix/bin/nix-channel --list | grep -q "^nixpkgs "; then
     $nix/bin/nix-channel --add https://nixos.org/channels/nixpkgs-unstable
 fi
 if [ -z "$_NIX_INSTALLER_TEST" ]; then
-    $nix/bin/nix-channel --update nixpkgs
+    if ! $nix/bin/nix-channel --update nixpkgs; then
+        echo "Fetching the nixpkgs channel failed. (Are you offline?)"
+        echo "To try again later, run \"nix-channel --update nixpkgs\"."
+    fi
 fi
 
 added=
+p=$HOME/.nix-profile/etc/profile.d/nix.sh
 if [ -z "$NIX_INSTALLER_NO_MODIFY_PROFILE" ]; then
-
     # Make the shell source nix.sh during login.
-    p=$HOME/.nix-profile/etc/profile.d/nix.sh
-
     for i in .bash_profile .bash_login .profile; do
         fn="$HOME/$i"
         if [ -w "$fn" ]; then
@@ -152,7 +155,6 @@ if [ -z "$NIX_INSTALLER_NO_MODIFY_PROFILE" ]; then
             break
         fi
     done
-
 fi
 
 if [ -z "$added" ]; then

scripts/install-systemd-multi-user.sh

@@ -9,6 +9,38 @@ readonly SERVICE_DEST=/etc/systemd/system/nix-daemon.service
 readonly SOCKET_SRC=/lib/systemd/system/nix-daemon.socket
 readonly SOCKET_DEST=/etc/systemd/system/nix-daemon.socket
 
+
+# Path for the systemd override unit file to contain the proxy settings
+readonly SERVICE_OVERRIDE=${SERVICE_DEST}.d/override.conf
+
+create_systemd_override() {
+     header "Configuring proxy for the nix-daemon service"
+    _sudo "create directory for systemd unit override" mkdir -p "$(dirname $SERVICE_OVERRIDE)"
+    cat <<EOF | _sudo "create systemd unit override" tee "$SERVICE_OVERRIDE"
+[Service]
+$1
+EOF
+}
+
+# Gather all non-empty proxy environment variables into a string
+create_systemd_proxy_env() {
+    vars="http_proxy https_proxy ftp_proxy no_proxy HTTP_PROXY HTTPS_PROXY FTP_PROXY NO_PROXY"
+    for v in $vars; do
+        if [ "x${!v:-}" != "x" ]; then
+            echo "Environment=${v}=${!v}"
+        fi
+    done
+}
+
+handle_network_proxy() {
+    # Create a systemd unit override with proxy environment variables
+    # if any proxy environment variables are not empty.
+    PROXY_ENV_STRING=$(create_systemd_proxy_env)
+    if [ -n "${PROXY_ENV_STRING}" ]; then
+        create_systemd_override "${PROXY_ENV_STRING}"
+    fi
+}
+
 poly_validate_assumptions() {
     if [ "$(uname -s)" != "Linux" ]; then
         failure "This script is for use with Linux!"
@@ -47,6 +79,8 @@ poly_configure_nix_daemon_service() {
     _sudo "to set up the nix-daemon socket service" \
           systemctl enable "/nix/var/nix/profiles/default$SOCKET_SRC"
 
+    handle_network_proxy
+
     _sudo "to load the systemd unit for nix-daemon" \
           systemctl daemon-reload
 
@@ -54,7 +88,7 @@ poly_configure_nix_daemon_service() {
           systemctl start nix-daemon.socket
 
     _sudo "to start the nix-daemon.service" \
-          systemctl start nix-daemon.service
+          systemctl restart nix-daemon.service
 
 }
 

scripts/install.in

@@ -18,7 +18,7 @@ cleanup() {
 trap cleanup EXIT INT QUIT TERM
 
 require_util() {
-    type "$1" > /dev/null 2>&1 || command -v "$1" > /dev/null 2>&1 ||
+    command -v "$1" > /dev/null 2>&1 ||
         oops "you do not have '$1' installed, which I need to $2"
 }
 
@@ -30,22 +30,22 @@ case "$(uname -s).$(uname -m)" in
     *) oops "sorry, there is no binary distribution of Nix for your platform";;
 esac
 
-url="https://nixos.org/releases/nix/nix-@nixVersion@/nix-@nixVersion@-$system.tar.bz2"
+url="https://releases.nixos.org/nix/nix-@nixVersion@/nix-@nixVersion@-$system.tar.xz"
 
-tarball="$tmpDir/$(basename "$tmpDir/nix-@nixVersion@-$system.tar.bz2")"
+tarball="$tmpDir/$(basename "$tmpDir/nix-@nixVersion@-$system.tar.xz")"
 
 require_util curl "download the binary tarball"
-require_util bzcat "decompress the binary tarball"
 require_util tar "unpack the binary tarball"
+require_util xz "unpack the binary tarball"
 
 echo "downloading Nix @nixVersion@ binary tarball for $system from '$url' to '$tmpDir'..."
 curl -L "$url" -o "$tarball" || oops "failed to download '$url'"
 
-if type sha256sum > /dev/null 2>&1; then
+if command -v sha256sum > /dev/null 2>&1; then
     hash2="$(sha256sum -b "$tarball" | cut -c1-64)"
-elif type shasum > /dev/null 2>&1; then
+elif command -v shasum > /dev/null 2>&1; then
     hash2="$(shasum -a 256 -b "$tarball" | cut -c1-64)"
-elif type openssl > /dev/null 2>&1; then
+elif command -v openssl > /dev/null 2>&1; then
     hash2="$(openssl dgst -r -sha256 "$tarball" | cut -c1-64)"
 else
     oops "cannot verify the SHA-256 hash of '$url'; you need one of 'shasum', 'sha256sum', or 'openssl'"
@@ -57,7 +57,7 @@ fi
 
 unpack=$tmpDir/unpack
 mkdir -p "$unpack"
-< "$tarball" bzcat | tar -xf - -C "$unpack" || oops "failed to unpack '$url'"
+tar -xJf "$tarball" -C "$unpack" || oops "failed to unpack '$url'"
 
 script=$(echo "$unpack"/*/install)
 

scripts/nix-profile-daemon.sh.in

@@ -2,54 +2,8 @@
 if [ -n "${__ETC_PROFILE_NIX_SOURCED:-}" ]; then return; fi
 __ETC_PROFILE_NIX_SOURCED=1
 
-# Set up secure multi-user builds: non-root users build through the
-# Nix daemon.
-if [ "$USER" != root -o ! -w @localstatedir@/nix/db ]; then
-    export NIX_REMOTE=daemon
-fi
-
-export NIX_USER_PROFILE_DIR="@localstatedir@/nix/profiles/per-user/$USER"
 export NIX_PROFILES="@localstatedir@/nix/profiles/default $HOME/.nix-profile"
 
-# Set up the per-user profile.
-mkdir -m 0755 -p $NIX_USER_PROFILE_DIR
-if ! test -O "$NIX_USER_PROFILE_DIR"; then
-    echo "WARNING: bad ownership on $NIX_USER_PROFILE_DIR" >&2
-fi
-
-if test -w $HOME; then
-  if ! test -L $HOME/.nix-profile; then
-      if test "$USER" != root; then
-          ln -s $NIX_USER_PROFILE_DIR/profile $HOME/.nix-profile
-      else
-          # Root installs in the system-wide profile by default.
-          ln -s @localstatedir@/nix/profiles/default $HOME/.nix-profile
-      fi
-  fi
-
-  # Subscribe the root user to the NixOS channel by default.
-  if [ "$USER" = root -a ! -e $HOME/.nix-channels ]; then
-      echo "https://nixos.org/channels/nixpkgs-unstable nixpkgs" > $HOME/.nix-channels
-  fi
-
-  # Create the per-user garbage collector roots directory.
-  NIX_USER_GCROOTS_DIR=@localstatedir@/nix/gcroots/per-user/$USER
-  mkdir -m 0755 -p $NIX_USER_GCROOTS_DIR
-  if ! test -O "$NIX_USER_GCROOTS_DIR"; then
-      echo "WARNING: bad ownership on $NIX_USER_GCROOTS_DIR" >&2
-  fi
-
-  # Set up a default Nix expression from which to install stuff.
-  if [ ! -e $HOME/.nix-defexpr -o -L $HOME/.nix-defexpr ]; then
-      rm -f $HOME/.nix-defexpr
-      mkdir -p $HOME/.nix-defexpr
-      if [ "$USER" != root ]; then
-          ln -s @localstatedir@/nix/profiles/per-user/root/channels $HOME/.nix-defexpr/channels_root
-      fi
-  fi
-fi
-
-
 # Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
 if [ ! -z "${NIX_SSL_CERT_FILE:-}" ]; then
     : # Allow users to override the NIX_SSL_CERT_FILE
@@ -70,5 +24,4 @@ else
   done
 fi
 
-export NIX_PATH="nixpkgs=@localstatedir@/nix/profiles/per-user/root/channels/nixpkgs:@localstatedir@/nix/profiles/per-user/root/channels"
 export PATH="$HOME/.nix-profile/bin:@localstatedir@/nix/profiles/default/bin:$PATH"

scripts/nix-profile.sh.in

@@ -1,64 +1,13 @@
 if [ -n "$HOME" ] && [ -n "$USER" ]; then
-    __savedpath="$PATH"
-    export PATH=@coreutils@
 
     # Set up the per-user profile.
     # This part should be kept in sync with nixpkgs:nixos/modules/programs/shell.nix
 
     NIX_LINK=$HOME/.nix-profile
 
-    NIX_USER_PROFILE_DIR=@localstatedir@/nix/profiles/per-user/$USER
-
-    mkdir -m 0755 -p "$NIX_USER_PROFILE_DIR"
-
-    if [ "$(stat --printf '%u' "$NIX_USER_PROFILE_DIR")" != "$(id -u)" ]; then
-        echo "Nix: WARNING: bad ownership on "$NIX_USER_PROFILE_DIR", should be $(id -u)" >&2
-    fi
-
-    if [ -w "$HOME" ]; then
-        if ! [ -L "$NIX_LINK" ]; then
-            echo "Nix: creating $NIX_LINK" >&2
-            if [ "$USER" != root ]; then
-                if ! ln -s "$NIX_USER_PROFILE_DIR"/profile "$NIX_LINK"; then
-                    echo "Nix: WARNING: could not create $NIX_LINK -> $NIX_USER_PROFILE_DIR/profile" >&2
-                fi
-            else
-                # Root installs in the system-wide profile by default.
-                ln -s @localstatedir@/nix/profiles/default "$NIX_LINK"
-            fi
-        fi
-
-        # Subscribe the user to the unstable Nixpkgs channel by default.
-        if [ ! -e "$HOME/.nix-channels" ]; then
-            echo "https://nixos.org/channels/nixpkgs-unstable nixpkgs" > "$HOME/.nix-channels"
-        fi
-
-        # Create the per-user garbage collector roots directory.
-        __user_gcroots=@localstatedir@/nix/gcroots/per-user/"$USER"
-        mkdir -m 0755 -p "$__user_gcroots"
-        if [ "$(stat --printf '%u' "$__user_gcroots")" != "$(id -u)" ]; then
-            echo "Nix: WARNING: bad ownership on $__user_gcroots, should be $(id -u)" >&2
-        fi
-        unset __user_gcroots
-
-        # Set up a default Nix expression from which to install stuff.
-        __nix_defexpr="$HOME"/.nix-defexpr
-        [ -L "$__nix_defexpr" ] && rm -f "$__nix_defexpr"
-        mkdir -m 0755 -p "$__nix_defexpr"
-        if [ "$USER" != root ] && [ ! -L "$__nix_defexpr"/channels_root ]; then
-            ln -s @localstatedir@/nix/profiles/per-user/root/channels "$__nix_defexpr"/channels_root
-        fi
-        unset __nix_defexpr
-    fi
-
-    # Append ~/.nix-defexpr/channels/nixpkgs to $NIX_PATH so that
-    # <nixpkgs> paths work when the user has fetched the Nixpkgs
-    # channel.
-    export NIX_PATH="${NIX_PATH:+$NIX_PATH:}nixpkgs=$HOME/.nix-defexpr/channels/nixpkgs"
-
     # Set up environment.
     # This part should be kept in sync with nixpkgs:nixos/modules/programs/environment.nix
-    NIX_PROFILES="@localstatedir@/nix/profiles/default $NIX_USER_PROFILE_DIR"
+    export NIX_PROFILES="@localstatedir@/nix/profiles/default $HOME/.nix-profile"
 
     # Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
     if [ -e /etc/ssl/certs/ca-certificates.crt ]; then # NixOS, Ubuntu, Debian, Gentoo, Arch
@@ -79,6 +28,6 @@ if [ -n "$HOME" ] && [ -n "$USER" ]; then
         export MANPATH="$NIX_LINK/share/man:$MANPATH"
     fi
 
-    export PATH="$NIX_LINK/bin:$__savedpath"
-    unset __savedpath NIX_LINK NIX_USER_PROFILE_DIR NIX_PROFILES
+    export PATH="$NIX_LINK/bin:$PATH"
+    unset NIX_LINK
 fi

shell.nix

@@ -1,13 +1,13 @@
 { useClang ? false }:
 
-with import (builtins.fetchGit { url = https://github.com/NixOS/nixpkgs-channels.git; ref = "nixos-19.03"; }) {};
+with import (builtins.fetchTarball https://github.com/NixOS/nixpkgs/archive/nixos-20.03-small.tar.gz) {};
 
 with import ./release-common.nix { inherit pkgs; };
 
 (if useClang then clangStdenv else stdenv).mkDerivation {
   name = "nix";
 
-  buildInputs = buildDeps ++ tarballDeps ++ perlDeps;
+  buildInputs = buildDeps ++ propagatedDeps ++ perlDeps ++ [ pkgs.rustfmt ];
 
   inherit configureFlags;