Make nix search lazier

Only 4 evals left \o/

.github/workflows/test.yml

@@ -20,7 +20,8 @@ jobs:
         name: '${{ env.CACHIX_NAME }}'
         signingKey: '${{ secrets.CACHIX_SIGNING_KEY }}'
         authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
-    - run: nix-build -A checks.$(nix-instantiate --eval -E '(builtins.currentSystem)')
+    #- run: nix flake check
+    - run: nix-build -A checks.$(if [[ `uname` = Linux ]]; then echo x86_64-linux; else echo x86_64-darwin; fi)
   check_cachix:
     name: Cachix secret present for installer tests
     runs-on: ubuntu-latest

.gitignore

@@ -15,7 +15,6 @@ perl/Makefile.config
 /doc/manual/*.1
 /doc/manual/*.5
 /doc/manual/*.8
-/doc/manual/generated/*
 /doc/manual/nix.json
 /doc/manual/conf-file.json
 /doc/manual/builtins.json
@@ -57,6 +56,9 @@ perl/Makefile.config
 
 /src/nix-prefetch-url/nix-prefetch-url
 
+# /src/nix-daemon/
+/src/nix-daemon/nix-daemon
+
 /src/nix-collect-garbage/nix-collect-garbage
 
 # /src/nix-channel/
@@ -74,6 +76,7 @@ perl/Makefile.config
 # /tests/
 /tests/test-tmp
 /tests/common.sh
+/tests/dummy
 /tests/result*
 /tests/restricted-innocent
 /tests/shell

Makefile

@@ -12,7 +12,6 @@ makefiles = \
   src/resolve-system-dependencies/local.mk \
   scripts/local.mk \
   misc/bash/local.mk \
-  misc/fish/local.mk \
   misc/zsh/local.mk \
   misc/systemd/local.mk \
   misc/launchd/local.mk \
@@ -33,4 +32,4 @@ endif
 
 include mk/lib.mk
 
-GLOBAL_CXXFLAGS += -g -Wall -include config.h -std=c++17 -I src
+GLOBAL_CXXFLAGS += -g -Wall -include config.h -std=c++17

Makefile.config.in

@@ -1,4 +1,3 @@
-HOST_OS = @host_os@
 AR = @AR@
 BDW_GC_LIBS = @BDW_GC_LIBS@
 BOOST_LDFLAGS = @BOOST_LDFLAGS@

benchmark.sh

@@ -0,0 +1,53 @@
+#!/bin/sh
+
+set -euo pipefail
+set -x
+
+callNix () {
+    nix \
+        --experimental-features "nix-command flakes" \
+        --store /tmp/nix \
+        "$@"
+}
+
+callBuild () {
+    callNix \
+        eval --impure --file "$THINGTOBENCH" drvPath \
+        "$@"
+}
+getCompletions () {
+    NIX_GET_COMPLETIONS=6 callNix build "github:NixOS/nixpkgs?rev=ad0d20345219790533ebe06571f82ed6b034db31#firef" "$@"
+}
+runSearch () {
+    callNix search "github:NixOS/nixpkgs?rev=ad0d20345219790533ebe06571f82ed6b034db31" firefox "$@"
+}
+
+noCache () {
+    "$@" --option eval-cache false
+}
+coldCache () {
+    if [[ -e ~/.cache/nix/eval-cache-v2 || -e ~/.cache/nix/eval-cache-v3 ]]; then
+        echo "Error: The cache should be clean"
+        exit 1
+    fi
+    "$@"
+}
+
+run_all () {
+
+    mkdir -p "$out"
+
+    NIX_SHOW_STATS=1 NIX_SHOW_STATS_PATH=$out/eval-stats.json bash $0 noCache callBuild
+
+    hyperfine \
+        --warmup 2 \
+        --export-csv "$out/result.csv" \
+        --export-json "$out/result.json" \
+        --export-markdown "$out/result.md" \
+        --style basic \
+        --prepare '' "bash $0 noCache callBuild" \
+        --prepare 'rm -rf ~/.cache/nix/' "bash $0 coldCache callBuild" \
+        --prepare '' "bash $0 callBuild"
+}
+
+"$@"

boehmgc-coroutine-sp-fallback.diff

@@ -1,42 +0,0 @@
-diff --git a/pthread_stop_world.c b/pthread_stop_world.c
-index 1cee6a0b..46c3acd9 100644
---- a/pthread_stop_world.c
-+++ b/pthread_stop_world.c
-@@ -674,6 +674,8 @@ GC_INNER void GC_push_all_stacks(void)
-     struct GC_traced_stack_sect_s *traced_stack_sect;
-     pthread_t self = pthread_self();
-     word total_size = 0;
-+    size_t stack_limit;
-+    pthread_attr_t pattr;
- 
-     if (!EXPECT(GC_thr_initialized, TRUE))
-       GC_thr_init();
-@@ -723,6 +725,28 @@ GC_INNER void GC_push_all_stacks(void)
-           hi = p->altstack + p->altstack_size;
-           /* FIXME: Need to scan the normal stack too, but how ? */
-           /* FIXME: Assume stack grows down */
-+        } else {
-+          if (pthread_getattr_np(p->id, &pattr)) {
-+            ABORT("GC_push_all_stacks: pthread_getattr_np failed!");
-+          }
-+          if (pthread_attr_getstacksize(&pattr, &stack_limit)) {
-+            ABORT("GC_push_all_stacks: pthread_attr_getstacksize failed!");
-+          }
-+          // When a thread goes into a coroutine, we lose its original sp until
-+          // control flow returns to the thread.
-+          // While in the coroutine, the sp points outside the thread stack,
-+          // so we can detect this and push the entire thread stack instead,
-+          // as an approximation.
-+          // We assume that the coroutine has similarly added its entire stack.
-+          // This could be made accurate by cooperating with the application
-+          // via new functions and/or callbacks.
-+          #ifndef STACK_GROWS_UP
-+            if (lo >= hi || lo < hi - stack_limit) { // sp outside stack
-+              lo = hi - stack_limit;
-+            }
-+          #else
-+          #error "STACK_GROWS_UP not supported in boost_coroutine2 (as of june 2021), so we don't support it in Nix."
-+          #endif
-         }
-         GC_push_all_stack_sections(lo, hi, traced_stack_sect);
- #       ifdef STACK_GROWS_UP

configure.ac

@@ -32,6 +32,14 @@ AC_ARG_WITH(system, AS_HELP_STRING([--with-system=SYSTEM],[Platform identifier (
         system="$machine_name-`echo $host_os | "$SED" -e's/@<:@0-9.@:>@*$//g'`";;
    esac])
 
+sys_name=$(uname -s | tr 'A-Z ' 'a-z_')
+
+case $sys_name in
+    cygwin*)
+        sys_name=cygwin
+        ;;
+esac
+
 AC_MSG_RESULT($system)
 AC_SUBST(system)
 AC_DEFINE_UNQUOTED(SYSTEM, ["$system"], [platform identifier ('cpu-os')])
@@ -55,12 +63,10 @@ AC_SYS_LARGEFILE
 
 # Solaris-specific stuff.
 AC_STRUCT_DIRENT_D_TYPE
-case "$host_os" in
-  solaris*)
+if test "$sys_name" = sunos; then
     # Solaris requires -lsocket -lnsl for network functions
-    LDFLAGS="-lsocket -lnsl $LDFLAGS"
-    ;;
-esac
+    LIBS="-lsocket -lnsl $LIBS"
+fi
 
 
 # Check for pubsetbuf.
@@ -144,7 +150,7 @@ int main() {
 }]])], 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
-    LDFLAGS="-latomic $LDFLAGS"
+    LIBS="-latomic $LIBS"
 fi
 
 PKG_PROG_PKG_CONFIG
@@ -204,31 +210,28 @@ AC_SUBST(HAVE_LIBCPUID, [$have_libcpuid])
 
 
 # Look for libseccomp, required for Linux sandboxing.
-case "$host_os" in
-  linux*)
-    AC_ARG_ENABLE([seccomp-sandboxing],
-                  AS_HELP_STRING([--disable-seccomp-sandboxing],[Don't build support for seccomp sandboxing (only recommended if your arch doesn't support libseccomp yet!)
-                                ]))
-    if test "x$enable_seccomp_sandboxing" != "xno"; then
-      PKG_CHECK_MODULES([LIBSECCOMP], [libseccomp],
-                        [CXXFLAGS="$LIBSECCOMP_CFLAGS $CXXFLAGS"])
-      have_seccomp=1
-      AC_DEFINE([HAVE_SECCOMP], [1], [Whether seccomp is available and should be used for sandboxing.])
-    else
-      have_seccomp=
-    fi
-    ;;
-  *)
+if test "$sys_name" = linux; then
+  AC_ARG_ENABLE([seccomp-sandboxing],
+                AS_HELP_STRING([--disable-seccomp-sandboxing],[Don't build support for seccomp sandboxing (only recommended if your arch doesn't support libseccomp yet!)
+                              ]))
+  if test "x$enable_seccomp_sandboxing" != "xno"; then
+    PKG_CHECK_MODULES([LIBSECCOMP], [libseccomp],
+                      [CXXFLAGS="$LIBSECCOMP_CFLAGS $CXXFLAGS"])
+    have_seccomp=1
+    AC_DEFINE([HAVE_SECCOMP], [1], [Whether seccomp is available and should be used for sandboxing.])
+  else
     have_seccomp=
-    ;;
-esac
+  fi
+else
+  have_seccomp=
+fi
 AC_SUBST(HAVE_SECCOMP, [$have_seccomp])
 
 
 # Look for aws-cpp-sdk-s3.
 AC_LANG_PUSH(C++)
 AC_CHECK_HEADERS([aws/s3/S3Client.h],
-  [AC_DEFINE([ENABLE_S3], [1], [Whether to enable S3 support via aws-sdk-cpp.]) enable_s3=1],
+  [AC_DEFINE([ENABLE_S3], [1], [Whether to enable S3 support via aws-sdk-cpp.]) enable_s3=1], 
   [AC_DEFINE([ENABLE_S3], [0], [Whether to enable S3 support via aws-sdk-cpp.]) enable_s3=])
 AC_SUBST(ENABLE_S3, [$enable_s3])
 AC_LANG_POP(C++)
@@ -271,11 +274,9 @@ AC_CHECK_FUNCS([strsignal posix_fallocate sysconf])
 
 # This is needed if bzip2 is a static library, and the Nix libraries
 # are dynamic.
-case "${host_os}" in
-  darwin*)
+if test "$(uname)" = "Darwin"; then
     LDFLAGS="-all_load $LDFLAGS"
-    ;;
-esac
+fi
 
 
 AC_ARG_WITH(sandbox-shell, AS_HELP_STRING([--with-sandbox-shell=PATH],[path of a statically-linked shell to use as /bin/sh in sandboxes]),

doc/manual/generate-builtins.nix

@@ -6,11 +6,9 @@ builtins:
 concatStrings (map
   (name:
     let builtin = builtins.${name}; in
-    "<dt><code>${name} "
-    + concatStringsSep " " (map (s: "<var>${s}</var>") builtin.args)
-    + "</code></dt>"
-    + "<dd>\n\n"
-    + builtin.doc
-    + "\n\n</dd>"
+    "  - `builtins.${name}` " + concatStringsSep " " (map (s: "*${s}*") builtin.args)
+    + "  \n\n"
+    + concatStrings (map (s: "    ${s}\n") (splitLines builtin.doc)) + "\n\n"
   )
   (attrNames builtins))
+

doc/manual/local.mk

@@ -1,5 +1,7 @@
 ifeq ($(doc_generate),yes)
 
+MANUAL_SRCS := $(call rwildcard, $(d)/src, *.md)
+
 # Generate man pages.
 man-pages := $(foreach n, \
   nix-env.1 nix-build.1 nix-shell.1 nix-store.1 nix-instantiate.1 \
@@ -62,7 +64,6 @@ $(d)/conf-file.json: $(bindir)/nix
 $(d)/src/expressions/builtins.md: $(d)/builtins.json $(d)/generate-builtins.nix $(d)/src/expressions/builtins-prefix.md $(bindir)/nix
 	@cat doc/manual/src/expressions/builtins-prefix.md > $@.tmp
 	$(trace-gen) $(nix-eval) --expr 'import doc/manual/generate-builtins.nix (builtins.fromJSON (builtins.readFile $<))' >> $@.tmp
-	@cat doc/manual/src/expressions/builtins-suffix.md >> $@.tmp
 	@mv $@.tmp $@
 
 $(d)/builtins.json: $(bindir)/nix
@@ -73,28 +74,17 @@ $(d)/builtins.json: $(bindir)/nix
 install: $(docdir)/manual/index.html
 
 # Generate 'nix' manpages.
-install: $(mandir)/man1/nix3-manpages
-man: doc/manual/generated/man1/nix3-manpages
-all: doc/manual/generated/man1/nix3-manpages
-
-$(mandir)/man1/nix3-manpages: doc/manual/generated/man1/nix3-manpages
-	@mkdir -p $$(dirname $@)
-	$(trace-install) install -m 0644 $$(dirname $<)/* $$(dirname $@)
-
-doc/manual/generated/man1/nix3-manpages: $(d)/src/command-ref/new-cli
-	@mkdir -p $$(dirname $@)
+install: $(d)/src/command-ref/new-cli
 	$(trace-gen) for i in doc/manual/src/command-ref/new-cli/*.md; do \
 	  name=$$(basename $$i .md); \
-	  tmpFile=$$(mktemp); \
 	  if [[ $$name = SUMMARY ]]; then continue; fi; \
-	  printf "Title: %s\n\n" "$$name" > $$tmpFile; \
-	  cat $$i >> $$tmpFile; \
-	  lowdown -sT man -M section=1 $$tmpFile -o $$(dirname $@)/$$name.1; \
-	  rm $$tmpFile; \
+	  printf "Title: %s\n\n" "$$name" > $$i.tmp; \
+	  cat $$i >> $$i.tmp; \
+	  lowdown -sT man -M section=1 $$i.tmp -o $(mandir)/man1/$$name.1; \
 	done
-	touch $@
 
 $(docdir)/manual/index.html: $(MANUAL_SRCS) $(d)/book.toml $(d)/custom.css $(d)/src/SUMMARY.md $(d)/src/command-ref/new-cli $(d)/src/command-ref/conf-file.md $(d)/src/expressions/builtins.md
 	$(trace-gen) RUST_LOG=warn mdbook build doc/manual -d $(docdir)/manual
+	@cp doc/manual/highlight.pack.js $(docdir)/manual/highlight.js
 
 endif

doc/manual/src/command-ref/env-common.md

@@ -10,39 +10,35 @@ Most Nix commands interpret the following environment variables:
     A colon-separated list of directories used to look up Nix
     expressions enclosed in angle brackets (i.e., `<path>`). For
     instance, the value
-
+    
         /home/eelco/Dev:/etc/nixos
-
+    
     will cause Nix to look for paths relative to `/home/eelco/Dev` and
     `/etc/nixos`, in this order. It is also possible to match paths
     against a prefix. For example, the value
-
+    
         nixpkgs=/home/eelco/Dev/nixpkgs-branch:/etc/nixos
-
+    
     will cause Nix to search for `<nixpkgs/path>` in
     `/home/eelco/Dev/nixpkgs-branch/path` and `/etc/nixos/nixpkgs/path`.
-
+    
     If a path in the Nix search path starts with `http://` or
     `https://`, it is interpreted as the URL of a tarball that will be
     downloaded and unpacked to a temporary location. The tarball must
     consist of a single top-level directory. For example, setting
     `NIX_PATH` to
-
-        nixpkgs=https://github.com/NixOS/nixpkgs/archive/master.tar.gz
-
-    tells Nix to download and use the current contents of the
-    `master` branch in the `nixpkgs` repository.
-
-    The URLs of the tarballs from the official nixos.org channels (see
-    [the manual for `nix-channel`](nix-channel.md)) can be abbreviated
-    as `channel:<channel-name>`.  For instance, the following two
-    values of `NIX_PATH` are equivalent:
-
-        nixpkgs=channel:nixos-21.05
-        nixpkgs=https://nixos.org/channels/nixos-21.05/nixexprs.tar.xz
-
-    The Nix search path can also be extended using the `-I` option to
-    many Nix commands, which takes precedence over `NIX_PATH`.
+    
+        nixpkgs=https://github.com/NixOS/nixpkgs/archive/nixos-15.09.tar.gz
+    
+    tells Nix to download the latest revision in the Nixpkgs/NixOS 15.09
+    channel.
+    
+    A following shorthand can be used to refer to the official channels:
+    
+        nixpkgs=channel:nixos-15.09
+    
+    The search path can be extended using the `-I` option, which takes
+    precedence over `NIX_PATH`.
 
   - `NIX_IGNORE_SYMLINK_STORE`\
     Normally, the Nix store directory (typically `/nix/store`) is not
@@ -54,7 +50,7 @@ Most Nix commands interpret the following environment variables:
     builds are deployed to machines where `/nix/store` resolves
     differently. If you are sure that you’re not going to do that, you
     can set `NIX_IGNORE_SYMLINK_STORE` to `1`.
-
+    
     Note that if you’re symlinking the Nix store so that you can put it
     on another file system than the root file system, on Linux you’re
     better off using `bind` mount points, e.g.,
@@ -63,7 +59,7 @@ Most Nix commands interpret the following environment variables:
     $ mkdir /nix
     $ mount -o bind /mnt/otherdisk/nix /nix
     ```
-
+    
     Consult the mount 8 manual page for details.
 
   - `NIX_STORE_DIR`\

doc/manual/src/expressions/builtins-prefix.md

@@ -9,8 +9,7 @@ scope. Instead, you can access them through the `builtins` built-in
 value, which is a set that contains all built-in functions and values.
 For instance, `derivation` is also available as `builtins.derivation`.
 
-<dl>
-  <dt><code>derivation <var>attrs</var></code>;
-      <code>builtins.derivation <var>attrs</var></code></dt>
-  <dd><p><var>derivation</var> in described in
-         <a href="derivations.md">its own section</a>.</p></dd>
+  - `derivation` *attrs*; `builtins.derivation` *attrs*\
+
+    `derivation` is described in [its own section](derivations.md).
+

doc/manual/src/expressions/builtins-suffix.md

@@ -1 +0,0 @@
-</dl>

flake.lock

@@ -19,11 +19,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1628689438,
-        "narHash": "sha256-YMINW6YmubHZVdliGsAJpnnMYXRrvppv59LgwtnyYhs=",
+        "lastModified": 1622593737,
+        "narHash": "sha256-9loxFJg85AbzJrSkU4pE/divZ1+zOxDy2FSjlrufCB8=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "f6551e1efa261568c82b76c3a582b2c2ceb1f53f",
+        "rev": "bb8a5e54845012ed1375ffd5f317d2fdf434b20e",
         "type": "github"
       },
       "original": {

flake.nix

@@ -20,8 +20,6 @@
       linuxSystems = linux64BitSystems ++ [ "i686-linux" ];
       systems = linuxSystems ++ [ "x86_64-darwin" "aarch64-darwin" ];
 
-      crossSystems = [ "armv6l-linux" "armv7l-linux" ];
-
       forAllSystems = f: nixpkgs.lib.genAttrs systems (system: f system);
 
       # Memoize nixpkgs for different platforms for efficiency.
@@ -81,7 +79,7 @@
             buildPackages.mercurial
             buildPackages.jq
           ]
-          ++ lib.optionals stdenv.hostPlatform.isLinux [(buildPackages.util-linuxMinimal or buildPackages.utillinuxMinimal)];
+          ++ lib.optionals stdenv.isLinux [(pkgs.util-linuxMinimal or pkgs.utillinuxMinimal)];
 
         buildDeps =
           [ curl
@@ -89,12 +87,13 @@
             openssl sqlite
             libarchive
             boost
+            nlohmann_json
             lowdown
             gmock
           ]
           ++ lib.optionals stdenv.isLinux [libseccomp]
           ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium
-          ++ lib.optional stdenv.hostPlatform.isx86_64 libcpuid;
+          ++ lib.optional stdenv.isx86_64 libcpuid;
 
         awsDeps = lib.optional (stdenv.isLinux || stdenv.isDarwin)
           (aws-sdk-cpp.override {
@@ -103,13 +102,7 @@
           });
 
         propagatedDeps =
-          [ ((boehmgc.override {
-              enableLargeConfig = true;
-            }).overrideAttrs(o: {
-              patches = (o.patches or []) ++ [
-                ./boehmgc-coroutine-sp-fallback.diff
-              ];
-            }))
+          [ (boehmgc.override { enableLargeConfig = true; })
           ];
 
         perlDeps =
@@ -140,11 +133,10 @@
 
             substitute ${./scripts/install.in} $out/install \
               ${pkgs.lib.concatMapStrings
-                (system: let
-                    tarball = if builtins.elem system crossSystems then self.hydraJobs.binaryTarballCross.x86_64-linux.${system} else self.hydraJobs.binaryTarball.${system};
-                  in '' \
-                  --replace '@tarballHash_${system}@' $(nix --experimental-features nix-command hash-file --base16 --type sha256 ${tarball}/*.tar.xz) \
-                  --replace '@tarballPath_${system}@' $(tarballPath ${tarball}/*.tar.xz) \
+                (system:
+                  '' \
+                  --replace '@tarballHash_${system}@' $(nix --experimental-features nix-command hash-file --base16 --type sha256 ${self.hydraJobs.binaryTarball.${system}}/*.tar.xz) \
+                  --replace '@tarballPath_${system}@' $(tarballPath ${self.hydraJobs.binaryTarball.${system}}/*.tar.xz) \
                   ''
                 )
                 systems
@@ -182,77 +174,6 @@
 
       };
 
-      binaryTarball = buildPackages: nix: pkgs: let
-        inherit (pkgs) cacert;
-        installerClosureInfo = buildPackages.closureInfo { rootPaths = [ nix cacert ]; };
-      in
-
-      buildPackages.runCommand "nix-binary-tarball-${version}"
-        { #nativeBuildInputs = lib.optional (system != "aarch64-linux") shellcheck;
-          meta.description = "Distribution-independent Nix bootstrap binaries for ${pkgs.system}";
-        }
-        ''
-          cp ${installerClosureInfo}/registration $TMPDIR/reginfo
-          cp ${./scripts/create-darwin-volume.sh} $TMPDIR/create-darwin-volume.sh
-          substitute ${./scripts/install-nix-from-closure.sh} $TMPDIR/install \
-            --subst-var-by nix ${nix} \
-            --subst-var-by cacert ${cacert}
-
-          substitute ${./scripts/install-darwin-multi-user.sh} $TMPDIR/install-darwin-multi-user.sh \
-            --subst-var-by nix ${nix} \
-            --subst-var-by cacert ${cacert}
-          substitute ${./scripts/install-systemd-multi-user.sh} $TMPDIR/install-systemd-multi-user.sh \
-            --subst-var-by nix ${nix} \
-            --subst-var-by cacert ${cacert}
-          substitute ${./scripts/install-multi-user.sh} $TMPDIR/install-multi-user \
-            --subst-var-by nix ${nix} \
-            --subst-var-by cacert ${cacert}
-
-          if type -p shellcheck; then
-            # SC1090: Don't worry about not being able to find
-            #         $nix/etc/profile.d/nix.sh
-            shellcheck --exclude SC1090 $TMPDIR/install
-            shellcheck $TMPDIR/create-darwin-volume.sh
-            shellcheck $TMPDIR/install-darwin-multi-user.sh
-            shellcheck $TMPDIR/install-systemd-multi-user.sh
-
-            # SC1091: Don't panic about not being able to source
-            #         /etc/profile
-            # SC2002: Ignore "useless cat" "error", when loading
-            #         .reginfo, as the cat is a much cleaner
-            #         implementation, even though it is "useless"
-            # SC2116: Allow ROOT_HOME=$(echo ~root) for resolving
-            #         root's home directory
-            shellcheck --external-sources \
-              --exclude SC1091,SC2002,SC2116 $TMPDIR/install-multi-user
-          fi
-
-          chmod +x $TMPDIR/install
-          chmod +x $TMPDIR/create-darwin-volume.sh
-          chmod +x $TMPDIR/install-darwin-multi-user.sh
-          chmod +x $TMPDIR/install-systemd-multi-user.sh
-          chmod +x $TMPDIR/install-multi-user
-          dir=nix-${version}-${pkgs.system}
-          fn=$out/$dir.tar.xz
-          mkdir -p $out/nix-support
-          echo "file binary-dist $fn" >> $out/nix-support/hydra-build-products
-          tar cvfJ $fn \
-            --owner=0 --group=0 --mode=u+rw,uga+r \
-            --absolute-names \
-            --hard-dereference \
-            --transform "s,$TMPDIR/install,$dir/install," \
-            --transform "s,$TMPDIR/create-darwin-volume.sh,$dir/create-darwin-volume.sh," \
-            --transform "s,$TMPDIR/reginfo,$dir/.reginfo," \
-            --transform "s,$NIX_STORE,$dir/store,S" \
-            $TMPDIR/install \
-            $TMPDIR/create-darwin-volume.sh \
-            $TMPDIR/install-darwin-multi-user.sh \
-            $TMPDIR/install-systemd-multi-user.sh \
-            $TMPDIR/install-multi-user \
-            $TMPDIR/reginfo \
-            $(cat ${installerClosureInfo}/store-paths)
-        '';
-
     in {
 
       # A Nixpkgs overlay that overrides the 'nix' and
@@ -308,7 +229,7 @@
             echo "doc manual $doc/share/doc/nix/manual" >> $doc/nix-support/hydra-build-products
           '';
 
-          doInstallCheck = true;
+          doInstallCheck = false;
           installCheckFlags = "sysconfdir=$(out)/etc";
 
           separateDebugInfo = true;
@@ -333,9 +254,9 @@
                 xz
                 pkgs.perl
                 boost
+                nlohmann_json
               ]
-              ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium
-              ++ lib.optional stdenv.isDarwin darwin.apple_sdk.frameworks.Security;
+              ++ lib.optional (stdenv.isLinux || stdenv.isDarwin) libsodium;
 
             configureFlags = ''
               --with-dbi=${perlPackages.DBI}/${pkgs.perl.libPrefix}
@@ -363,7 +284,7 @@
 
           outputs = [ "out" "bin" "dev" ];
 
-          nativeBuildInputs = [ buildPackages.which ];
+          nativeBuildInputs = [ which ];
 
           configurePhase = ''
               ${if (stdenv.isDarwin && stdenv.isAarch64) then "echo \"HAVE_SANDBOX_INIT=false\" > configure.local" else ""}
@@ -373,6 +294,13 @@
             '';
         };
 
+        nix-benchmarks = prev.runCommandNoCC "nix-benchmarks" {
+          buildInputs = [ final.nix prev.hyperfine ];
+          THINGTOBENCH = ./thingToBench.nix;
+          NIX_PATH="nixpkgs=${prev.path}";
+        } ''
+          bash ${./benchmark.sh} run_all
+        '';
       };
 
       hydraJobs = {
@@ -382,33 +310,92 @@
 
         buildStatic = nixpkgs.lib.genAttrs linux64BitSystems (system: self.packages.${system}.nix-static);
 
-        buildCross = nixpkgs.lib.genAttrs crossSystems (crossSystem:
-          nixpkgs.lib.genAttrs ["x86_64-linux"] (system: self.packages.${system}."nix-${crossSystem}"));
-
         # Perl bindings for various platforms.
         perlBindings = nixpkgs.lib.genAttrs systems (system: self.packages.${system}.nix.perl-bindings);
 
         # Binary tarball for various platforms, containing a Nix store
         # with the closure of 'nix' package, and the second half of
         # the installation script.
-        binaryTarball = nixpkgs.lib.genAttrs systems (system: binaryTarball nixpkgsFor.${system} nixpkgsFor.${system}.nix nixpkgsFor.${system});
+        binaryTarball = nixpkgs.lib.genAttrs systems (system:
 
-        binaryTarballCross = nixpkgs.lib.genAttrs ["x86_64-linux"] (system: builtins.listToAttrs (map (crossSystem: {
-          name = crossSystem;
-          value = let
-            nixpkgsCross = import nixpkgs {
-              inherit system crossSystem;
-              overlays = [ self.overlay ];
-            };
-          in binaryTarball nixpkgsFor.${system} self.packages.${system}."nix-${crossSystem}" nixpkgsCross;
-        }) crossSystems));
+          with nixpkgsFor.${system};
+
+          let
+            installerClosureInfo = closureInfo { rootPaths = [ nix cacert ]; };
+          in
+
+          runCommand "nix-binary-tarball-${version}"
+            { #nativeBuildInputs = lib.optional (system != "aarch64-linux") shellcheck;
+              meta.description = "Distribution-independent Nix bootstrap binaries for ${system}";
+            }
+            ''
+              cp ${installerClosureInfo}/registration $TMPDIR/reginfo
+              cp ${./scripts/create-darwin-volume.sh} $TMPDIR/create-darwin-volume.sh
+              substitute ${./scripts/install-nix-from-closure.sh} $TMPDIR/install \
+                --subst-var-by nix ${nix} \
+                --subst-var-by cacert ${cacert}
+
+              substitute ${./scripts/install-darwin-multi-user.sh} $TMPDIR/install-darwin-multi-user.sh \
+                --subst-var-by nix ${nix} \
+                --subst-var-by cacert ${cacert}
+              substitute ${./scripts/install-systemd-multi-user.sh} $TMPDIR/install-systemd-multi-user.sh \
+                --subst-var-by nix ${nix} \
+                --subst-var-by cacert ${cacert}
+              substitute ${./scripts/install-multi-user.sh} $TMPDIR/install-multi-user \
+                --subst-var-by nix ${nix} \
+                --subst-var-by cacert ${cacert}
+
+              if type -p shellcheck; then
+                # SC1090: Don't worry about not being able to find
+                #         $nix/etc/profile.d/nix.sh
+                shellcheck --exclude SC1090 $TMPDIR/install
+                shellcheck $TMPDIR/create-darwin-volume.sh
+                shellcheck $TMPDIR/install-darwin-multi-user.sh
+                shellcheck $TMPDIR/install-systemd-multi-user.sh
+
+                # SC1091: Don't panic about not being able to source
+                #         /etc/profile
+                # SC2002: Ignore "useless cat" "error", when loading
+                #         .reginfo, as the cat is a much cleaner
+                #         implementation, even though it is "useless"
+                # SC2116: Allow ROOT_HOME=$(echo ~root) for resolving
+                #         root's home directory
+                shellcheck --external-sources \
+                  --exclude SC1091,SC2002,SC2116 $TMPDIR/install-multi-user
+              fi
+
+              chmod +x $TMPDIR/install
+              chmod +x $TMPDIR/create-darwin-volume.sh
+              chmod +x $TMPDIR/install-darwin-multi-user.sh
+              chmod +x $TMPDIR/install-systemd-multi-user.sh
+              chmod +x $TMPDIR/install-multi-user
+              dir=nix-${version}-${system}
+              fn=$out/$dir.tar.xz
+              mkdir -p $out/nix-support
+              echo "file binary-dist $fn" >> $out/nix-support/hydra-build-products
+              tar cvfJ $fn \
+                --owner=0 --group=0 --mode=u+rw,uga+r \
+                --absolute-names \
+                --hard-dereference \
+                --transform "s,$TMPDIR/install,$dir/install," \
+                --transform "s,$TMPDIR/create-darwin-volume.sh,$dir/create-darwin-volume.sh," \
+                --transform "s,$TMPDIR/reginfo,$dir/.reginfo," \
+                --transform "s,$NIX_STORE,$dir/store,S" \
+                $TMPDIR/install \
+                $TMPDIR/create-darwin-volume.sh \
+                $TMPDIR/install-darwin-multi-user.sh \
+                $TMPDIR/install-systemd-multi-user.sh \
+                $TMPDIR/install-multi-user \
+                $TMPDIR/reginfo \
+                $(cat ${installerClosureInfo}/store-paths)
+            '');
 
         # The first half of the installation script. This is uploaded
         # to https://nixos.org/nix/install. It downloads the binary
         # tarball for the user's system and calls the second half of the
         # installation script.
-        installerScript = installScriptFor [ "x86_64-linux" "i686-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" "armv6l-linux" "armv7l-linux" ];
-        installerScriptForGHA = installScriptFor [ "x86_64-linux" "x86_64-darwin" "armv6l-linux" "armv7l-linux"];
+        installerScript = installScriptFor [ "x86_64-linux" "i686-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
+        installerScriptForGHA = installScriptFor [ "x86_64-linux" "x86_64-darwin" ];
 
         # Line coverage analysis.
         coverage =
@@ -502,14 +489,11 @@
             # `NIX_DAEMON_SOCKET_PATH` which is required for the tests to work
             # againstLatestStable = testNixVersions pkgs pkgs.nix pkgs.nixStable;
           } "touch $out";
-      } // (if system == "x86_64-linux" then (builtins.listToAttrs (map (crossSystem: {
-        name = "binaryTarball-${crossSystem}";
-        value = self.hydraJobs.binaryTarballCross.${system}.${crossSystem};
-      }) crossSystems)) else {}));
+      });
 
       packages = forAllSystems (system: {
-        inherit (nixpkgsFor.${system}) nix;
-      } // (nixpkgs.lib.optionalAttrs (builtins.elem system linux64BitSystems) {
+        inherit (nixpkgsFor.${system}) nix nix-benchmarks;
+      } // nixpkgs.lib.optionalAttrs (builtins.elem system linux64BitSystems) {
         nix-static = let
           nixpkgs = nixpkgsFor.${system}.pkgsStatic;
         in with commonDeps nixpkgs; nixpkgs.stdenv.mkDerivation {
@@ -547,49 +531,8 @@
           stripAllList = ["bin"];
 
           strictDeps = true;
-
-          hardeningDisable = [ "pie" ];
         };
-      } // builtins.listToAttrs (map (crossSystem: {
-        name = "nix-${crossSystem}";
-        value = let
-          nixpkgsCross = import nixpkgs {
-            inherit system crossSystem;
-            overlays = [ self.overlay ];
-          };
-        in with commonDeps nixpkgsCross; nixpkgsCross.stdenv.mkDerivation {
-          name = "nix-${version}";
-
-          src = self;
-
-          VERSION_SUFFIX = versionSuffix;
-
-          outputs = [ "out" "dev" "doc" ];
-
-          nativeBuildInputs = nativeBuildDeps;
-          buildInputs = buildDeps ++ propagatedDeps;
-
-          configureFlags = [ "--sysconfdir=/etc" "--disable-doc-gen" ];
-
-          enableParallelBuilding = true;
-
-          makeFlags = "profiledir=$(out)/etc/profile.d";
-
-          doCheck = true;
-
-          installFlags = "sysconfdir=$(out)/etc";
-
-          postInstall = ''
-            mkdir -p $doc/nix-support
-            echo "doc manual $doc/share/doc/nix/manual" >> $doc/nix-support/hydra-build-products
-            mkdir -p $out/nix-support
-            echo "file binary-dist $out/bin/nix" >> $out/nix-support/hydra-build-products
-          '';
-
-          doInstallCheck = true;
-          installCheckFlags = "sysconfdir=$(out)/etc";
-        };
-      }) crossSystems)));
+      });
 
       defaultPackage = forAllSystems (system: self.packages.${system}.nix);
 

maintainers/upload-release.pl

@@ -83,12 +83,12 @@ sub downloadFile {
 
     if (!-e $tmpFile) {
         print STDERR "downloading $srcFile to $tmpFile...\n";
-        system("NIX_REMOTE=https://cache.nixos.org/ nix store cat '$srcFile' > '$tmpFile'") == 0
+        system("NIX_REMOTE=https://cache.nixos.org/ nix cat-store '$srcFile' > '$tmpFile'") == 0
             or die "unable to fetch $srcFile\n";
     }
 
     my $sha256_expected = $buildInfo->{buildproducts}->{$productNr}->{sha256hash} or die;
-    my $sha256_actual = `nix hash file --base16 --type sha256 '$tmpFile'`;
+    my $sha256_actual = `nix hash-file --base16 --type sha256 '$tmpFile'`;
     chomp $sha256_actual;
     if ($sha256_expected ne $sha256_actual) {
         print STDERR "file $tmpFile is corrupt, got $sha256_actual, expected $sha256_expected\n";
@@ -110,9 +110,6 @@ downloadFile("binaryTarball.i686-linux", "1");
 downloadFile("binaryTarball.x86_64-linux", "1");
 downloadFile("binaryTarball.aarch64-linux", "1");
 downloadFile("binaryTarball.x86_64-darwin", "1");
-downloadFile("binaryTarball.aarch64-darwin", "1");
-downloadFile("binaryTarballCross.x86_64-linux.armv6l-linux", "1");
-downloadFile("binaryTarballCross.x86_64-linux.armv7l-linux", "1");
 downloadFile("installerScript", "1");
 
 for my $fn (glob "$tmpDir/*") {
@@ -156,7 +153,6 @@ write_file("$nixpkgsDir/nixos/modules/installer/tools/nix-fallback-paths.nix",
            "  i686-linux = \"" . getStorePath("build.i686-linux") . "\";\n" .
            "  aarch64-linux = \"" . getStorePath("build.aarch64-linux") . "\";\n" .
            "  x86_64-darwin = \"" . getStorePath("build.x86_64-darwin") . "\";\n" .
-           "  aarch64-darwin = \"" . getStorePath("build.aarch64-darwin") . "\";\n" .
            "}\n");
 
 system("cd $nixpkgsDir && git commit -a -m 'nix-fallback-paths.nix: Update to $version'") == 0 or die;

misc/fish/completion.fish

@@ -1,37 +0,0 @@
-function _nix_complete
-  # Get the current command up to a cursor.
-  # - Behaves correctly even with pipes and nested in commands like env.
-  # - TODO: Returns the command verbatim (does not interpolate variables).
-  #   That might not be optimal for arguments like -f.
-  set -l nix_args (commandline --current-process --tokenize --cut-at-cursor)
-  # --cut-at-cursor with --tokenize removes the current token so we need to add it separately.
-  # https://github.com/fish-shell/fish-shell/issues/7375
-  # Can be an empty string.
-  set -l current_token (commandline --current-token --cut-at-cursor)
-
-  # Nix wants the index of the argv item to complete but the $nix_args variable
-  # also contains the program name (argv[0]) so we would need to subtract 1.
-  # But the variable also misses the current token so it cancels out.
-  set -l nix_arg_to_complete (count $nix_args)
-
-  env NIX_GET_COMPLETIONS=$nix_arg_to_complete $nix_args $current_token
-end
-
-function _nix_accepts_files
-  set -l response (_nix_complete)
-  # First line is either filenames or no-filenames.
-  test $response[1] = 'filenames'
-end
-
-function _nix
-  set -l response (_nix_complete)
-  # Skip the first line since it handled by _nix_accepts_files.
-  # Tail lines each contain a command followed by a tab character and, optionally, a description.
-  # This is also the format fish expects.
-  string collect -- $response[2..-1]
-end
-
-# Disable file path completion if paths do not belong in the current context.
-complete --command nix --condition 'not _nix_accepts_files' --no-files
-
-complete --command nix --arguments '(_nix)'

misc/fish/local.mk

@@ -1 +0,0 @@
-$(eval $(call install-file-as, $(d)/completion.fish, $(datarootdir)/fish/vendor_completions.d/nix.fish, 0644))

misc/launchd/local.mk

@@ -1,4 +1,4 @@
-ifdef HOST_DARWIN
+ifeq ($(OS), Darwin)
 
   $(eval $(call install-data-in, $(d)/org.nixos.nix-daemon.plist, $(prefix)/Library/LaunchDaemons))
 

misc/systemd/local.mk

@@ -1,4 +1,4 @@
-ifdef HOST_LINUX
+ifeq ($(OS), Linux)
 
   $(foreach n, nix-daemon.socket nix-daemon.service, $(eval $(call install-file-in, $(d)/$(n), $(prefix)/lib/systemd/system, 0644)))
 

misc/upstart/local.mk

@@ -1,4 +1,4 @@
-ifdef HOST_LINUX
+ifeq ($(OS), Linux)
 
   $(foreach n, nix-daemon.conf, $(eval $(call install-file-in, $(d)/$(n), $(sysconfdir)/init, 0644)))
 

misc/zsh/completion.zsh

@@ -1,5 +1,3 @@
-#compdef nix
-
 function _nix() {
   local ifs_bk="$IFS"
   local input=("${(Q)words[@]}")
@@ -20,4 +18,4 @@ function _nix() {
   _describe 'nix' suggestions
 }
 
-_nix "$@"
+compdef _nix nix

mk/lib.mk

@@ -10,25 +10,8 @@ bin-scripts :=
 noinst-scripts :=
 man-pages :=
 install-tests :=
+OS = $(shell uname -s)
 
-ifdef HOST_OS
-  HOST_KERNEL = $(firstword $(subst -, ,$(HOST_OS)))
-  ifeq ($(HOST_KERNEL), cygwin)
-    HOST_CYGWIN = 1
-  endif
-  ifeq ($(patsubst darwin%,,$(HOST_KERNEL)),)
-    HOST_DARWIN = 1
-  endif
-  ifeq ($(patsubst freebsd%,,$(HOST_KERNEL)),)
-    HOST_FREEBSD = 1
-  endif
-  ifeq ($(HOST_KERNEL), linux)
-    HOST_LINUX = 1
-  endif
-  ifeq ($(patsubst solaris%,,$(HOST_KERNEL)),)
-    HOST_SOLARIS = 1
-  endif
-endif
 
 # Hack to define a literal space.
 space :=
@@ -67,16 +50,16 @@ endif
 BUILD_SHARED_LIBS ?= 1
 
 ifeq ($(BUILD_SHARED_LIBS), 1)
-  ifdef HOST_CYGWIN
+  ifeq (CYGWIN,$(findstring CYGWIN,$(OS)))
     GLOBAL_CFLAGS += -U__STRICT_ANSI__ -D_GNU_SOURCE
     GLOBAL_CXXFLAGS += -U__STRICT_ANSI__ -D_GNU_SOURCE
   else
     GLOBAL_CFLAGS += -fPIC
     GLOBAL_CXXFLAGS += -fPIC
   endif
-  ifndef HOST_DARWIN
-   ifndef HOST_SOLARIS
-    ifndef HOST_FREEBSD
+  ifneq ($(OS), Darwin)
+   ifneq ($(OS), SunOS)
+    ifneq ($(OS), FreeBSD)
      GLOBAL_LDFLAGS += -Wl,--no-copy-dt-needed-entries
     endif
    endif

mk/libraries.mk

@@ -1,9 +1,9 @@
 libs-list :=
 
-ifdef HOST_DARWIN
+ifeq ($(OS), Darwin)
   SO_EXT = dylib
 else
-  ifdef HOST_CYGWIN
+  ifeq (CYGWIN,$(findstring CYGWIN,$(OS)))
     SO_EXT = dll
   else
     SO_EXT = so
@@ -59,7 +59,7 @@ define build-library
   $(1)_OBJS := $$(addprefix $(buildprefix), $$(addsuffix .o, $$(basename $$(_srcs))))
   _libs := $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_PATH))
 
-  ifdef HOST_CYGWIN
+  ifeq (CYGWIN,$(findstring CYGWIN,$(OS)))
     $(1)_INSTALL_DIR ?= $$(bindir)
   else
     $(1)_INSTALL_DIR ?= $$(libdir)
@@ -73,18 +73,18 @@ define build-library
   ifeq ($(BUILD_SHARED_LIBS), 1)
 
     ifdef $(1)_ALLOW_UNDEFINED
-      ifdef HOST_DARWIN
+      ifeq ($(OS), Darwin)
         $(1)_LDFLAGS += -undefined suppress -flat_namespace
       endif
     else
-      ifndef HOST_DARWIN
-        ifndef HOST_CYGWIN
+      ifneq ($(OS), Darwin)
+        ifneq (CYGWIN,$(findstring CYGWIN,$(OS)))
           $(1)_LDFLAGS += -Wl,-z,defs
         endif
       endif
     endif
 
-    ifndef HOST_DARWIN
+    ifneq ($(OS), Darwin)
       $(1)_LDFLAGS += -Wl,-soname=$$($(1)_NAME).$(SO_EXT)
     endif
 
@@ -93,7 +93,7 @@ define build-library
     $$($(1)_PATH): $$($(1)_OBJS) $$(_libs) | $$(_d)/
 	$$(trace-ld) $(CXX) -o $$(abspath $$@) -shared $$(LDFLAGS) $$(GLOBAL_LDFLAGS) $$($(1)_OBJS) $$($(1)_LDFLAGS) $$($(1)_LDFLAGS_PROPAGATED) $$(foreach lib, $$($(1)_LIBS), $$($$(lib)_LDFLAGS_USE)) $$($(1)_LDFLAGS_UNINSTALLED)
 
-    ifndef HOST_DARWIN
+    ifneq ($(OS), Darwin)
       $(1)_LDFLAGS_USE += -Wl,-rpath,$$(abspath $$(_d))
     endif
     $(1)_LDFLAGS_USE += -L$$(_d) -l$$(patsubst lib%,%,$$(strip $$($(1)_NAME)))
@@ -108,7 +108,7 @@ define build-library
 	$$(trace-ld) $(CXX) -o $$@ -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 $$($(1)_NAME)))
-    ifndef HOST_DARWIN
+    ifneq ($(OS), Darwin)
       ifeq ($(SET_RPATH_TO_LIBS), 1)
         $(1)_LDFLAGS_USE_INSTALLED += -Wl,-rpath,$$($(1)_INSTALL_DIR)
       else

nix-rust/local.mk

@@ -11,12 +11,12 @@ libnixrust_INSTALL_PATH := $(libdir)/libnixrust.$(SO_EXT)
 libnixrust_LDFLAGS_USE := -L$(d)/target/$(RUST_DIR) -lnixrust
 libnixrust_LDFLAGS_USE_INSTALLED := -L$(libdir) -lnixrust
 
-ifdef HOST_LINUX
+ifeq ($(OS), Linux)
 libnixrust_LDFLAGS_USE += -ldl
 libnixrust_LDFLAGS_USE_INSTALLED += -ldl
 endif
 
-ifdef HOST_DARWIN
+ifeq ($(OS), Darwin)
 libnixrust_BUILD_FLAGS = NIX_LDFLAGS="-undefined dynamic_lookup"
 else
 libnixrust_LDFLAGS_USE += -Wl,-rpath,$(abspath $(d)/target/$(RUST_DIR))
@@ -31,7 +31,7 @@ $(libnixrust_PATH): $(call rwildcard, $(d)/src, *.rs) $(d)/Cargo.toml
 
 $(libnixrust_INSTALL_PATH): $(libnixrust_PATH)
 	$(target-gen) cp $^ $@
-ifdef HOST_DARWIN
+ifeq ($(OS), Darwin)
 	install_name_tool -id $@ $@
 endif
 
@@ -40,7 +40,7 @@ clean: clean-rust
 clean-rust:
 	$(suppress) rm -rfv nix-rust/target
 
-ifndef HOST_DARWIN
+ifneq ($(OS), Darwin)
 check: rust-tests
 
 rust-tests:

perl/Makefile

@@ -1,6 +1,6 @@
 makefiles = local.mk
 
-GLOBAL_CXXFLAGS += -g -Wall -std=c++17 -I ../src
+GLOBAL_CXXFLAGS += -g -Wall -std=c++17
 
 -include Makefile.config
 

perl/Makefile.config.in

@@ -1,4 +1,3 @@
-HOST_OS = @host_os@
 CC = @CC@
 CFLAGS = @CFLAGS@
 CXX = @CXX@

perl/configure.ac

@@ -7,8 +7,6 @@ CXXFLAGS=
 AC_PROG_CC
 AC_PROG_CXX
 
-AC_CANONICAL_HOST
-
 # Use 64-bit file system calls so that we can support files > 2 GiB.
 AC_SYS_LARGEFILE
 

perl/lib/Nix/Store.pm

@@ -22,7 +22,6 @@ our @EXPORT = qw(
     derivationFromPath
     addTempRoot
     getBinDir getStoreDir
-    queryRawRealisation
 );
 
 our $VERSION = '0.15';

perl/lib/Nix/Store.xs

@@ -15,7 +15,6 @@
 #include "crypto.hh"
 
 #include <sodium.h>
-#include <nlohmann/json.hpp>
 
 
 using namespace nix;
@@ -121,18 +120,6 @@ SV * queryPathInfo(char * path, int base32)
             croak("%s", e.what());
         }
 
-SV * queryRawRealisation(char * outputId)
-    PPCODE:
-      try {
-        auto realisation = store()->queryRealisation(DrvOutput::parse(outputId));
-        if (realisation)
-            XPUSHs(sv_2mortal(newSVpv(realisation->toJSON().dump().c_str(), 0)));
-        else
-            XPUSHs(sv_2mortal(newSVpv("", 0)));
-      } catch (Error & e) {
-        croak("%s", e.what());
-      }
-
 
 SV * queryPathFromHashPart(char * hashPart)
     PPCODE:

perl/local.mk

@@ -28,7 +28,7 @@ Store_CXXFLAGS = \
 
 Store_LDFLAGS := $(SODIUM_LIBS) $(NIX_LIBS)
 
-ifdef HOST_CYGWIN
+ifeq (CYGWIN,$(findstring CYGWIN,$(OS)))
   archlib = $(shell perl -E 'use Config; print $$Config{archlib};')
   libperl = $(shell perl -E 'use Config; print $$Config{libperl};')
   Store_LDFLAGS += $(shell find ${archlib} -name ${libperl})

scripts/install-multi-user.sh

@@ -701,10 +701,7 @@ install_from_extracted_nix() {
         cd "$EXTRACTED_NIX_PATH"
 
         _sudo "to copy the basic Nix files to the new store at $NIX_ROOT/store" \
-              cp -RLp ./store/* "$NIX_ROOT/store/"
-
-        _sudo "to make the new store non-writable at $NIX_ROOT/store" \
-              chmod -R ugo-w "$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"

scripts/install-nix-from-closure.sh

@@ -106,11 +106,12 @@ while [ $# -gt 0 ]; do
                 echo ""
                 echo " --no-channel-add:    Don't add any channels. nixpkgs-unstable is installed by default."
                 echo ""
-                echo " --no-modify-profile: Don't modify the user profile to automatically load nix."
+                echo " --no-modify-profile: Skip channel installation. When not provided nixpkgs-unstable"
+                echo "                      is installed by default."
                 echo ""
                 echo " --daemon-user-count: Number of build users to create. Defaults to 32."
                 echo ""
-                echo " --nix-extra-conf-file: Path to nix.conf to prepend when installing /etc/nix/nix.conf"
+                echo " --nix-extra-conf-file: Path to nix.conf to prepend when installing /etc/nix.conf"
                 echo ""
                 if [ -n "${INVOKED_FROM_INSTALL_IN:-}" ]; then
                     echo " --tarball-url-prefix URL: Base URL to download the Nix tarball from."

scripts/install.in

@@ -40,23 +40,13 @@ case "$(uname -s).$(uname -m)" in
         path=@tarballPath_aarch64-linux@
         system=aarch64-linux
         ;;
-    Linux.armv6l_linux)
-        hash=@tarballHash_armv6l-linux@
-        path=@tarballPath_armv6l-linux@
-        system=armv6l-linux
-        ;;
-    Linux.armv7l_linux)
-        hash=@tarballHash_armv7l-linux@
-        path=@tarballPath_armv7l-linux@
-        system=armv7l-linux
-        ;;
     Darwin.x86_64)
         hash=@tarballHash_x86_64-darwin@
         path=@tarballPath_x86_64-darwin@
         system=x86_64-darwin
         ;;
     Darwin.arm64|Darwin.aarch64)
-        hash=@tarballHash_aarch64-darwin@
+        hash=@binaryTarball_aarch64-darwin@
         path=@tarballPath_aarch64-darwin@
         system=aarch64-darwin
         ;;

src/build-remote/build-remote.cc

@@ -270,23 +270,14 @@ connected:
 
         {
             Activity act(*logger, lvlTalkative, actUnknown, fmt("copying dependencies to '%s'", storeUri));
-            copyPaths(*store, *sshStore, store->parseStorePathSet(inputs), NoRepair, NoCheckSigs, substitute);
+            copyPaths(store, ref<Store>(sshStore), store->parseStorePathSet(inputs), NoRepair, NoCheckSigs, substitute);
         }
 
         uploadLock = -1;
 
         auto drv = store->readDerivation(*drvPath);
         auto outputHashes = staticOutputHashes(*store, drv);
-
-        // Hijack the inputs paths of the derivation to include all the paths
-        // that come from the `inputDrvs` set.
-        // We don’t do that for the derivations whose `inputDrvs` is empty
-        // because
-        // 1. It’s not needed
-        // 2. Changing the `inputSrcs` set changes the associated output ids,
-        //  which break CA derivations
-        if (!drv.inputDrvs.empty())
-            drv.inputSrcs = store->parseStorePathSet(inputs);
+        drv.inputSrcs = store->parseStorePathSet(inputs);
 
         auto result = sshStore->buildDerivation(*drvPath, drv);
 
@@ -321,7 +312,7 @@ connected:
             if (auto localStore = store.dynamic_pointer_cast<LocalStore>())
                 for (auto & path : missingPaths)
                     localStore->locksHeld.insert(store->printStorePath(path)); /* FIXME: ugly */
-            copyPaths(*sshStore, *store, missingPaths, NoRepair, NoCheckSigs, NoSubstitute);
+            copyPaths(ref<Store>(sshStore), store, missingPaths, NoRepair, NoCheckSigs, NoSubstitute);
         }
         // XXX: Should be done as part of `copyPaths`
         for (auto & realisation : missingRealisations) {

src/libcmd/command.cc

@@ -54,30 +54,6 @@ void StoreCommand::run()
     run(getStore());
 }
 
-EvalCommand::EvalCommand()
-{
-}
-
-EvalCommand::~EvalCommand()
-{
-    if (evalState)
-        evalState->printStats();
-}
-
-ref<Store> EvalCommand::getEvalStore()
-{
-    if (!evalStore)
-        evalStore = evalStoreUrl ? openStore(*evalStoreUrl) : getStore();
-    return ref<Store>(evalStore);
-}
-
-ref<EvalState> EvalCommand::getEvalState()
-{
-    if (!evalState)
-        evalState = std::make_shared<EvalState>(searchPath, getEvalStore(), getStore());
-    return ref<EvalState>(evalState);
-}
-
 BuiltPathsCommand::BuiltPathsCommand(bool recursive)
     : recursive(recursive)
 {
@@ -115,7 +91,7 @@ void BuiltPathsCommand::run(ref<Store> store)
         for (auto & p : store->queryAllValidPaths())
             paths.push_back(BuiltPath::Opaque{p});
     } else {
-        paths = toBuiltPaths(getEvalStore(), store, realiseMode, operateOn, installables);
+        paths = toBuiltPaths(store, realiseMode, operateOn, installables);
         if (recursive) {
             // XXX: This only computes the store path closure, ignoring
             // intermediate realisations
@@ -212,7 +188,7 @@ void MixProfile::updateProfile(const BuiltPaths & buildables)
     }
 
     if (result.size() != 1)
-        throw UsageError("'--profile' requires that the arguments produce a single store path, but there are %d", result.size());
+        throw Error("'--profile' requires that the arguments produce a single store path, but there are %d", result.size());
 
     updateProfile(result[0]);
 }

src/libcmd/command.hh

@@ -45,18 +45,11 @@ private:
 
 struct EvalCommand : virtual StoreCommand, MixEvalArgs
 {
-    EvalCommand();
-
-    ~EvalCommand();
-
-    ref<Store> getEvalStore();
-
     ref<EvalState> getEvalState();
 
-private:
-    std::shared_ptr<Store> evalStore;
-
     std::shared_ptr<EvalState> evalState;
+
+    ~EvalCommand();
 };
 
 struct MixFlakeOptions : virtual Args, EvalCommand
@@ -223,21 +216,15 @@ static RegisterCommand registerCommand2(std::vector<std::string> && name)
     return RegisterCommand(std::move(name), [](){ return make_ref<T>(); });
 }
 
-BuiltPaths build(ref<Store> evalStore, ref<Store> store, Realise mode,
+BuiltPaths build(ref<Store> store, Realise mode,
     std::vector<std::shared_ptr<Installable>> installables, BuildMode bMode = bmNormal);
 
-std::set<StorePath> toStorePaths(
-    ref<Store> evalStore,
-    ref<Store> store,
-    Realise mode,
-    OperateOn operateOn,
+std::set<StorePath> toStorePaths(ref<Store> store,
+    Realise mode, OperateOn operateOn,
     std::vector<std::shared_ptr<Installable>> installables);
 
-StorePath toStorePath(
-    ref<Store> evalStore,
-    ref<Store> store,
-    Realise mode,
-    OperateOn operateOn,
+StorePath toStorePath(ref<Store> store,
+    Realise mode, OperateOn operateOn,
     std::shared_ptr<Installable> installable);
 
 std::set<StorePath> toDerivations(ref<Store> store,
@@ -245,7 +232,6 @@ std::set<StorePath> toDerivations(ref<Store> store,
     bool useDeriver = false);
 
 BuiltPaths toBuiltPaths(
-    ref<Store> evalStore,
     ref<Store> store,
     Realise mode,
     OperateOn operateOn,

src/libcmd/installables.cc

@@ -58,13 +58,9 @@ MixFlakeOptions::MixFlakeOptions()
 
     addFlag({
         .longName = "no-registries",
-        .description =
-          "Don't allow lookups in the flake registries. This option is deprecated; use `--no-use-registries`.",
+        .description = "Don't allow lookups in the flake registries.",
         .category = category,
-        .handler = {[&]() {
-            lockFlags.useRegistries = false;
-            warn("'--no-registries' is deprecated; use '--no-use-registries'");
-        }}
+        .handler = {&lockFlags.useRegistries, false}
     });
 
     addFlag({
@@ -175,50 +171,14 @@ Strings SourceExprCommand::getDefaultFlakeAttrPathPrefixes()
 
 void SourceExprCommand::completeInstallable(std::string_view prefix)
 {
-    if (file) {
-        evalSettings.pureEval = false;
-        auto state = getEvalState();
-        Expr *e = state->parseExprFromFile(
-            resolveExprPath(state->checkSourcePath(lookupFileArg(*state, *file)))
-        );
+    if (file) return; // FIXME
 
-        Value root;
-        state->eval(e, root);
-
-        auto autoArgs = getAutoArgs(*state);
-
-        std::string prefix_ = std::string(prefix);
-        auto sep = prefix_.rfind('.');
-        std::string searchWord;
-        if (sep != std::string::npos) {
-            searchWord = prefix_.substr(sep, std::string::npos);
-            prefix_ = prefix_.substr(0, sep);
-        } else {
-            searchWord = prefix_;
-            prefix_ = "";
-        }
-
-        Value &v1(*findAlongAttrPath(*state, prefix_, *autoArgs, root).first);
-        state->forceValue(v1);
-        Value v2;
-        state->autoCallFunction(*autoArgs, v1, v2);
-
-        if (v2.type() == nAttrs) {
-            for (auto & i : *v2.attrs) {
-                std::string name = i.name;
-                if (name.find(searchWord) == 0) {
-                    completions->add(i.name);
-                }
-            }
-        }
-    } else {
-        completeFlakeRefWithFragment(
-            getEvalState(),
-            lockFlags,
-            getDefaultFlakeAttrPathPrefixes(),
-            getDefaultFlakeAttrPaths(),
-            prefix);
-    }
+    completeFlakeRefWithFragment(
+        getEvalState(),
+        lockFlags,
+        getDefaultFlakeAttrPathPrefixes(),
+        getDefaultFlakeAttrPaths(),
+        prefix);
 }
 
 void completeFlakeRefWithFragment(
@@ -289,6 +249,19 @@ void completeFlakeRefWithFragment(
     completeFlakeRef(evalState->store, prefix);
 }
 
+ref<EvalState> EvalCommand::getEvalState()
+{
+    if (!evalState)
+        evalState = std::make_shared<EvalState>(searchPath, getStore());
+    return ref<EvalState>(evalState);
+}
+
+EvalCommand::~EvalCommand()
+{
+    if (evalState)
+        evalState->printStats();
+}
+
 void completeFlakeRef(ref<Store> store, std::string_view prefix)
 {
     if (prefix == "")
@@ -329,6 +302,14 @@ Installable::getCursors(EvalState & state)
     return {{evalCache->getRoot(), ""}};
 }
 
+std::pair<Value*, Pos> Installable::toValue(EvalState & state)
+{
+    auto values = toValues(state);
+    if (values.empty())
+        throw Error("cannot find flake attribute '%s'", what());
+    return {std::get<0>(values[0]), std::get<1>(values[0])};
+}
+
 std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>
 Installable::getCursor(EvalState & state)
 {
@@ -378,7 +359,6 @@ DerivedPaths InstallableValue::toDerivedPaths()
     DerivedPaths res;
 
     std::map<StorePath, std::set<std::string>> drvsToOutputs;
-    RealisedPath::Set drvsToCopy;
 
     // Group by derivation, helps with .all in particular
     for (auto & drv : toDerivations()) {
@@ -386,7 +366,6 @@ DerivedPaths InstallableValue::toDerivedPaths()
         if (outputName == "")
             throw Error("derivation '%s' lacks an 'outputName' attribute", state->store->printStorePath(drv.drvPath));
         drvsToOutputs[drv.drvPath].insert(outputName);
-        drvsToCopy.insert(drv.drvPath);
     }
 
     for (auto & i : drvsToOutputs)
@@ -407,11 +386,11 @@ struct InstallableAttrPath : InstallableValue
 
     std::string what() override { return attrPath; }
 
-    std::pair<Value *, Pos> toValue(EvalState & state) override
+    std::vector<std::tuple<Value *, Pos, std::string>> toValues(EvalState & state) override
     {
         auto [vRes, pos] = findAlongAttrPath(state, attrPath, *cmd.getAutoArgs(state), **v);
         state.forceValue(*vRes);
-        return {vRes, pos};
+        return {{vRes, pos, attrPath}};
     }
 
     virtual std::vector<InstallableValue::DerivationInfo> toDerivations() override;
@@ -457,12 +436,10 @@ Value * InstallableFlake::getFlakeOutputs(EvalState & state, const flake::Locked
 
     callFlake(state, lockedFlake, *vFlake);
 
-    auto aOutputs = vFlake->attrs->get(state.symbols.create("outputs"));
-    assert(aOutputs);
-
-    state.forceValue(*aOutputs->value);
-
-    return aOutputs->value;
+    auto vRes = state.allocValue();
+    auto gotField = state.lazyGetAttrField(*vFlake, {state.symbols.create("outputs")}, noPos, *vRes);
+    assert(gotField != EvalState::LazyValueType::Missing);
+    return vRes;
 }
 
 ref<eval_cache::EvalCache> openEvalCache(
@@ -529,25 +506,34 @@ std::tuple<std::string, FlakeRef, InstallableValue::DerivationInfo> InstallableF
     auto root = cache->getRoot();
 
     for (auto & attrPath : getActualAttrPaths()) {
-        auto attr = root->findAlongAttrPath(
-            parseAttrPath(*state, attrPath),
-            true
-        );
+        auto emptyArgs = state->allocBindings(0);
+        try {
+            auto [drvValue, pos] = findAlongAttrPath(
+                *state,
+                attrPath,
+                *emptyArgs,
+                *getFlakeOutputs(*state, *lockedFlake)
+            );
+            Value * v = state->allocValue();
+            if (!state->getAttrField(*drvValue, {state->sDrvPath}, pos, *v))
+                break;
+            auto drvPath = state->forceString(*v);
+            if (!state->getAttrField(*drvValue, {state->sOutPath}, pos, *v))
+                break;
+            auto outPath = state->forceString(*v);
+            if (!state->getAttrField(*drvValue, {state->sOutputName}, pos, *v))
+                break;
+            auto outputName = state->forceString(*v);
 
-        if (!attr) continue;
+            auto drvInfo = DerivationInfo{
+                state->store->parseStorePath(drvPath),
+                state->store->maybeParseStorePath(outPath),
+                outputName
+            };
 
-        if (!attr->isDerivation())
-            throw Error("flake output attribute '%s' is not a derivation", attrPath);
-
-        auto drvPath = attr->forceDerivation();
-
-        auto drvInfo = DerivationInfo{
-            std::move(drvPath),
-            state->store->maybeParseStorePath(attr->getAttr(state->sOutPath)->getString()),
-            attr->getAttr(state->sOutputName)->getString()
-        };
-
-        return {attrPath, lockedFlake->flake.lockedRef, std::move(drvInfo)};
+            return {attrPath, lockedFlake->flake.lockedRef, std::move(drvInfo)};
+        } catch (AttrPathNotFound & e) {
+        }
     }
 
     throw Error("flake '%s' does not provide attribute %s",
@@ -561,25 +547,22 @@ std::vector<InstallableValue::DerivationInfo> InstallableFlake::toDerivations()
     return res;
 }
 
-std::pair<Value *, Pos> InstallableFlake::toValue(EvalState & state)
+std::vector<std::tuple<Value *, Pos, std::string>>
+InstallableFlake::toValues(EvalState & state)
 {
-    auto lockedFlake = getLockedFlake();
-
-    auto vOutputs = getFlakeOutputs(state, *lockedFlake);
-
+    auto vOutputs = getFlakeOutputs(state, *getLockedFlake());
     auto emptyArgs = state.allocBindings(0);
 
+    std::vector<std::tuple<Value *, Pos, std::string>> res;
+
     for (auto & attrPath : getActualAttrPaths()) {
         try {
             auto [v, pos] = findAlongAttrPath(state, attrPath, *emptyArgs, *vOutputs);
-            state.forceValue(*v);
-            return {v, pos};
-        } catch (AttrPathNotFound & e) {
-        }
+            res.push_back({v, pos, attrPath});
+        } catch (Error &) {}
     }
 
-    throw Error("flake '%s' does not provide attribute %s",
-        flakeRef, showAttrPaths(getActualAttrPaths()));
+    return res;
 }
 
 std::vector<std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>>
@@ -602,10 +585,10 @@ InstallableFlake::getCursors(EvalState & state)
 
 std::shared_ptr<flake::LockedFlake> InstallableFlake::getLockedFlake() const
 {
-    flake::LockFlags lockFlagsApplyConfig = lockFlags;
-    lockFlagsApplyConfig.applyNixConfig = true;
     if (!_lockedFlake) {
-        _lockedFlake = std::make_shared<flake::LockedFlake>(lockFlake(*state, flakeRef, lockFlagsApplyConfig));
+        _lockedFlake = std::make_shared<flake::LockedFlake>(lockFlake(*state, flakeRef, lockFlags));
+        _lockedFlake->flake.config.apply();
+        // FIXME: send new config to the daemon.
     }
     return _lockedFlake;
 }
@@ -701,10 +684,10 @@ std::shared_ptr<Installable> SourceExprCommand::parseInstallable(
     return installables.front();
 }
 
-BuiltPaths getBuiltPaths(ref<Store> evalStore, ref<Store> store, const DerivedPaths & hopefullyBuiltPaths)
+BuiltPaths getBuiltPaths(ref<Store> store, DerivedPaths hopefullyBuiltPaths)
 {
     BuiltPaths res;
-    for (auto & b : hopefullyBuiltPaths)
+    for (auto& b : hopefullyBuiltPaths)
         std::visit(
             overloaded{
                 [&](DerivedPath::Opaque bo) {
@@ -712,13 +695,14 @@ BuiltPaths getBuiltPaths(ref<Store> evalStore, ref<Store> store, const DerivedPa
                 },
                 [&](DerivedPath::Built bfd) {
                     OutputPathMap outputs;
-                    auto drv = evalStore->readDerivation(bfd.drvPath);
-                    auto outputHashes = staticOutputHashes(*evalStore, drv); // FIXME: expensive
+                    auto drv = store->readDerivation(bfd.drvPath);
+                    auto outputHashes = staticOutputHashes(*store, drv);
                     auto drvOutputs = drv.outputsAndOptPaths(*store);
-                    for (auto & output : bfd.outputs) {
+                    for (auto& output : bfd.outputs) {
                         if (!outputHashes.count(output))
                             throw Error(
-                                "the derivation '%s' doesn't have an output named '%s'",
+                                "the derivation '%s' doesn't have an output "
+                                "named '%s'",
                                 store->printStorePath(bfd.drvPath), output);
                         if (settings.isExperimentalFeatureEnabled(
                                 "ca-derivations")) {
@@ -729,7 +713,7 @@ BuiltPaths getBuiltPaths(ref<Store> evalStore, ref<Store> store, const DerivedPa
                             if (!realisation)
                                 throw Error(
                                     "cannot operate on an output of unbuilt "
-                                    "content-addressed derivation '%s'",
+                                    "content-addresed derivation '%s'",
                                     outputId.to_string());
                             outputs.insert_or_assign(
                                 output, realisation->outPath);
@@ -750,7 +734,7 @@ BuiltPaths getBuiltPaths(ref<Store> evalStore, ref<Store> store, const DerivedPa
     return res;
 }
 
-BuiltPaths build(ref<Store> evalStore, ref<Store> store, Realise mode,
+BuiltPaths build(ref<Store> store, Realise mode,
     std::vector<std::shared_ptr<Installable>> installables, BuildMode bMode)
 {
     if (mode == Realise::Nothing)
@@ -766,21 +750,20 @@ BuiltPaths build(ref<Store> evalStore, ref<Store> store, Realise mode,
     if (mode == Realise::Nothing)
         printMissing(store, pathsToBuild, lvlError);
     else if (mode == Realise::Outputs)
-        store->buildPaths(pathsToBuild, bMode, evalStore);
+        store->buildPaths(pathsToBuild, bMode);
 
-    return getBuiltPaths(evalStore, store, pathsToBuild);
+    return getBuiltPaths(store, pathsToBuild);
 }
 
 BuiltPaths toBuiltPaths(
-    ref<Store> evalStore,
     ref<Store> store,
     Realise mode,
     OperateOn operateOn,
     std::vector<std::shared_ptr<Installable>> installables)
 {
-    if (operateOn == OperateOn::Output)
-        return build(evalStore, store, mode, installables);
-    else {
+    if (operateOn == OperateOn::Output) {
+        return build(store, mode, installables);
+    } else {
         if (mode == Realise::Nothing)
             settings.readOnlyMode = true;
 
@@ -791,27 +774,23 @@ BuiltPaths toBuiltPaths(
     }
 }
 
-StorePathSet toStorePaths(
-    ref<Store> evalStore,
-    ref<Store> store,
+StorePathSet toStorePaths(ref<Store> store,
     Realise mode, OperateOn operateOn,
     std::vector<std::shared_ptr<Installable>> installables)
 {
     StorePathSet outPaths;
-    for (auto & path : toBuiltPaths(evalStore, store, mode, operateOn, installables)) {
+    for (auto & path : toBuiltPaths(store, mode, operateOn, installables)) {
         auto thisOutPaths = path.outPaths();
         outPaths.insert(thisOutPaths.begin(), thisOutPaths.end());
     }
     return outPaths;
 }
 
-StorePath toStorePath(
-    ref<Store> evalStore,
-    ref<Store> store,
+StorePath toStorePath(ref<Store> store,
     Realise mode, OperateOn operateOn,
     std::shared_ptr<Installable> installable)
 {
-    auto paths = toStorePaths(evalStore, store, mode, operateOn, {installable});
+    auto paths = toStorePaths(store, mode, operateOn, {installable});
 
     if (paths.size() != 1)
         throw Error("argument '%s' should evaluate to one store path", installable->what());

src/libcmd/installables.hh

@@ -26,7 +26,7 @@ struct App
 struct UnresolvedApp
 {
     App unresolved;
-    App resolve(ref<Store> evalStore, ref<Store> store);
+    App resolve(ref<Store>);
 };
 
 struct Installable
@@ -41,10 +41,11 @@ struct Installable
 
     UnresolvedApp toApp(EvalState & state);
 
-    virtual std::pair<Value *, Pos> toValue(EvalState & state)
+    virtual std::vector<std::tuple<Value *, Pos, std::string>> toValues(EvalState & state)
     {
         throw Error("argument '%s' cannot be evaluated", what());
     }
+    std::pair<Value *, Pos> toValue(EvalState & state);
 
     /* Return a value only if this installable is a store path or a
        symlink to it. */
@@ -109,7 +110,7 @@ struct InstallableFlake : InstallableValue
 
     std::vector<DerivationInfo> toDerivations() override;
 
-    std::pair<Value *, Pos> toValue(EvalState & state) override;
+    std::vector<std::tuple<Value *, Pos, std::string>> toValues(EvalState & state) override;
 
     std::vector<std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>>
     getCursors(EvalState & state) override;

src/libcmd/local.mk

@@ -8,8 +8,8 @@ libcmd_SOURCES := $(wildcard $(d)/*.cc)
 
 libcmd_CXXFLAGS += -I src/libutil -I src/libstore -I src/libexpr -I src/libmain -I src/libfetchers
 
-libcmd_LDFLAGS = -llowdown -pthread
+libcmd_LDFLAGS = -llowdown
 
 libcmd_LIBS = libstore libutil libexpr libmain libfetchers
 
-$(eval $(call install-file-in, $(d)/nix-cmd.pc, $(libdir)/pkgconfig, 0644))
+$(eval $(call install-file-in, $(d)/nix-cmd.pc, $(prefix)/lib/pkgconfig, 0644))

src/libexpr/attr-path.cc

@@ -19,7 +19,7 @@ static Strings parseAttrPath(std::string_view s)
             ++i;
             while (1) {
                 if (i == s.end())
-                    throw ParseError("missing closing quote in selection path '%1%'", s);
+                    throw Error("missing closing quote in selection path '%1%'", s);
                 if (*i == '"') break;
                 cur.push_back(*i++);
             }
@@ -58,26 +58,23 @@ std::pair<Value *, Pos> findAlongAttrPath(EvalState & state, const string & attr
         Value * vNew = state.allocValue();
         state.autoCallFunction(autoArgs, *v, *vNew);
         v = vNew;
-        state.forceValue(*v);
 
         /* It should evaluate to either a set or an expression,
            according to what is specified in the attrPath. */
 
         if (!attrIndex) {
 
-            if (v->type() != nAttrs)
-                throw TypeError(
-                    "the expression selected by the selection path '%1%' should be a set but is %2%",
-                    attrPath,
-                    showType(*v));
             if (attr.empty())
                 throw Error("empty attribute name in selection path '%1%'", attrPath);
 
-            Bindings::iterator a = v->attrs->find(state.symbols.create(attr));
-            if (a == v->attrs->end())
+            auto v2 = state.allocValue();
+            auto gotField = state.lazyGetAttrField(*v, {state.symbols.create(attr)}, pos, *v2) != EvalState::LazyValueType::Missing;
+            if (!gotField)
                 throw AttrPathNotFound("attribute '%1%' in selection path '%2%' not found", attr, attrPath);
-            v = &*a->value;
-            pos = *a->pos;
+            v = v2;
+            /* Bindings::iterator a = v->attrs->find(state.symbols.create(attr)); */
+            /* v = &*a->value; */
+            /* pos = *a->pos; */
         }
 
         else {
@@ -100,7 +97,7 @@ std::pair<Value *, Pos> findAlongAttrPath(EvalState & state, const string & attr
 }
 
 
-Pos findPackageFilename(EvalState & state, Value & v, std::string what)
+Pos findDerivationFilename(EvalState & state, Value & v, std::string what)
 {
     Value * v2;
     try {
@@ -116,14 +113,14 @@ Pos findPackageFilename(EvalState & state, Value & v, std::string what)
 
     auto colon = pos.rfind(':');
     if (colon == std::string::npos)
-        throw ParseError("cannot parse meta.position attribute '%s'", pos);
+        throw Error("cannot parse meta.position attribute '%s'", pos);
 
     std::string filename(pos, 0, colon);
     unsigned int lineno;
     try {
         lineno = std::stoi(std::string(pos, colon + 1));
     } catch (std::invalid_argument & e) {
-        throw ParseError("cannot parse line number '%s'", pos);
+        throw Error("cannot parse line number '%s'", pos);
     }
 
     Symbol file = state.symbols.create(filename);

src/libexpr/attr-path.hh

@@ -14,7 +14,7 @@ std::pair<Value *, Pos> findAlongAttrPath(EvalState & state, const string & attr
     Bindings & autoArgs, Value & vIn);
 
 /* Heuristic to find the filename and lineno or a nix value. */
-Pos findPackageFilename(EvalState & state, Value & v, std::string what);
+Pos findDerivationFilename(EvalState & state, Value & v, std::string what);
 
 std::vector<Symbol> parseAttrPath(EvalState & state, std::string_view s);
 

src/libexpr/attr-set.hh

@@ -2,6 +2,7 @@
 
 #include "nixexpr.hh"
 #include "symbol-table.hh"
+#include "value-cache.hh"
 
 #include <algorithm>
 #include <optional>
@@ -36,6 +37,7 @@ class Bindings
 public:
     typedef uint32_t size_t;
     Pos *pos;
+    ValueCache eval_cache;
 
 private:
     size_t size_, capacity_;

src/libexpr/common-eval-args.cc

@@ -61,14 +61,6 @@ MixEvalArgs::MixEvalArgs()
             fetchers::overrideRegistry(from.input, to.input, extraAttrs);
         }}
     });
-
-    addFlag({
-        .longName = "eval-store",
-        .description = "The Nix store to use for evaluations.",
-        .category = category,
-        .labels = {"store-url"},
-        .handler = {&evalStoreUrl},
-    });
 }
 
 Bindings * MixEvalArgs::getAutoArgs(EvalState & state)

src/libexpr/common-eval-args.hh

@@ -16,9 +16,8 @@ struct MixEvalArgs : virtual Args
 
     Strings searchPath;
 
-    std::optional<std::string> evalStoreUrl;
-
 private:
+
     std::map<std::string, std::string> autoArgs;
 };
 

src/libexpr/context.cc

@@ -0,0 +1,21 @@
+#include "context.hh"
+
+namespace nix {
+
+/* Decode a context string ‘!<name>!<path>’ into a pair <path,
+   name>. */
+std::pair<string, string> decodeContext(std::string_view s)
+{
+    if (s.at(0) == '!') {
+        size_t index = s.find("!", 1);
+        return {std::string(s.substr(index + 1)), std::string(s.substr(1, index - 1))};
+    } else
+        return {s.at(0) == '/' ? std::string(s) : std::string(s.substr(1)), ""};
+}
+
+std::string encodeContext(std::string_view name, std::string_view path)
+{
+    return "!" + std::string(name) + "!" + std::string(path);
+}
+
+}

src/libexpr/context.hh

@@ -0,0 +1,11 @@
+#include "util.hh"
+
+namespace nix {
+
+/* Decode a context string ‘!<name>!<path>’ into a pair <path,
+   name>. */
+std::pair<string, string> decodeContext(std::string_view s);
+
+std::string encodeContext(std::string_view name, std::string_view path);
+
+}

src/libexpr/eval-inline.hh

@@ -46,6 +46,12 @@ void EvalState::forceValue(Value & v, const Pos & pos)
     }
     else if (v.isApp())
         callFunction(*v.app.left, *v.app.right, v, noPos);
+    else if (v.isCachedThunk()) {
+        auto evalCache = v.getEvalCache();
+        v.mkThunk(v.cachedThunk.thunk->env, v.cachedThunk.thunk->expr);
+        forceValue(v, pos);
+        v.setEvalCache(evalCache);
+    }
     else if (v.isBlackhole())
         throwEvalError(pos, "infinite recursion encountered");
 }

src/libexpr/eval.cc

@@ -1,4 +1,5 @@
 #include "eval.hh"
+#include "value-cache.hh"
 #include "hash.hh"
 #include "util.hh"
 #include "store-api.hh"
@@ -8,6 +9,7 @@
 #include "filetransfer.hh"
 #include "json.hh"
 #include "function-trace.hh"
+#include "value-cache.hh"
 
 #include <algorithm>
 #include <chrono>
@@ -64,11 +66,7 @@ static char * dupStringWithLen(const char * s, size_t size)
 
 RootValue allocRootValue(Value * v)
 {
-#if HAVE_BOEHMGC
     return std::allocate_shared<Value *>(traceable_allocator<Value *>(), v);
-#else
-    return std::make_shared<Value *>(v);
-#endif
 }
 
 
@@ -126,6 +124,7 @@ void printValue(std::ostream & str, std::set<const Value *> & active, const Valu
         str << "]";
         break;
     case tThunk:
+    case tCachedThunk:
     case tApp:
         str << "<CODE>";
         break;
@@ -197,7 +196,7 @@ string showType(const Value & v)
         case tPrimOpApp:
             return fmt("the partially applied built-in function '%s'", string(getPrimOp(v)->primOp->name));
         case tExternal: return v.external->showType();
-        case tThunk: return "a thunk";
+        case tThunk: case tCachedThunk: return "a thunk";
         case tApp: return "a function application";
         case tBlackhole: return "a black hole";
     default:
@@ -220,7 +219,7 @@ bool Value::isTrivial() const
     return
         internalType != tApp
         && internalType != tPrimOpApp
-        && (internalType != tThunk
+        && ((internalType != tThunk && internalType != tCachedThunk)
             || (dynamic_cast<ExprAttrs *>(thunk.expr)
                 && ((ExprAttrs *) thunk.expr)->dynamicAttrs.empty())
             || dynamic_cast<ExprLambda *>(thunk.expr)
@@ -237,34 +236,22 @@ static void * oomHandler(size_t requested)
 }
 
 class BoehmGCStackAllocator : public StackAllocator {
-    boost::coroutines2::protected_fixedsize_stack stack {
-        // We allocate 8 MB, the default max stack size on NixOS.
-        // A smaller stack might be quicker to allocate but reduces the stack
-        // depth available for source filter expressions etc.
-        std::max(boost::context::stack_traits::default_size(), static_cast<std::size_t>(8 * 1024 * 1024))
+  boost::coroutines2::protected_fixedsize_stack stack {
+    // We allocate 8 MB, the default max stack size on NixOS.
+    // A smaller stack might be quicker to allocate but reduces the stack
+    // depth available for source filter expressions etc.
+    std::max(boost::context::stack_traits::default_size(), static_cast<std::size_t>(8 * 1024 * 1024))
     };
 
-    // This is specific to boost::coroutines2::protected_fixedsize_stack.
-    // The stack protection page is included in sctx.size, so we have to
-    // subtract one page size from the stack size.
-    std::size_t pfss_usable_stack_size(boost::context::stack_context &sctx) {
-        return sctx.size - boost::context::stack_traits::page_size();
-    }
-
   public:
     boost::context::stack_context allocate() override {
         auto sctx = stack.allocate();
-
-        // Stacks generally start at a high address and grow to lower addresses.
-        // Architectures that do the opposite are rare; in fact so rare that
-        // boost_routine does not implement it.
-        // So we subtract the stack size.
-        GC_add_roots(static_cast<char *>(sctx.sp) - pfss_usable_stack_size(sctx), sctx.sp);
+        GC_add_roots(static_cast<char *>(sctx.sp) - sctx.size, sctx.sp);
         return sctx;
     }
 
     void deallocate(boost::context::stack_context sctx) override {
-        GC_remove_roots(static_cast<char *>(sctx.sp) - pfss_usable_stack_size(sctx), sctx.sp);
+        GC_remove_roots(static_cast<char *>(sctx.sp) - sctx.size, sctx.sp);
         stack.deallocate(sctx);
     }
 
@@ -378,10 +365,7 @@ static Strings parseNixPath(const string & s)
 }
 
 
-EvalState::EvalState(
-    const Strings & _searchPath,
-    ref<Store> store,
-    std::shared_ptr<Store> buildStore)
+EvalState::EvalState(const Strings & _searchPath, ref<Store> store)
     : sWith(symbols.create("<with>"))
     , sOutPath(symbols.create("outPath"))
     , sDrvPath(symbols.create("drvPath"))
@@ -414,7 +398,6 @@ EvalState::EvalState(
     , sEpsilon(symbols.create(""))
     , repair(NoRepair)
     , store(store)
-    , buildStore(buildStore ? buildStore : store)
     , regexCache(makeRegexCache())
     , baseEnv(allocEnv(128))
     , staticBaseEnv(false, 0)
@@ -462,6 +445,9 @@ EvalState::EvalState(
 
 EvalState::~EvalState()
 {
+    for (auto [_, cache] : evalCache) {
+        cache->commit();
+    }
 }
 
 
@@ -780,10 +766,18 @@ inline Value * EvalState::lookupVar(Env * env, const ExprVar & var, bool noEval)
 }
 
 
+std::atomic<uint64_t> nrValuesFreed{0};
+
+void finalizeValue(void * obj, void * data)
+{
+    nrValuesFreed++;
+}
+
 Value * EvalState::allocValue()
 {
     nrValues++;
     auto v = (Value *) allocBytes(sizeof(Value));
+    //GC_register_finalizer_no_order(v, finalizeValue, nullptr, nullptr, nullptr);
     return v;
 }
 
@@ -850,37 +844,39 @@ Value * Expr::maybeThunk(EvalState & state, Env & env)
 }
 
 
+unsigned long nrAvoided = 0;
+
 Value * ExprVar::maybeThunk(EvalState & state, Env & env)
 {
     Value * v = state.lookupVar(&env, *this, true);
     /* The value might not be initialised in the environment yet.
        In that case, ignore it. */
-    if (v) { state.nrAvoided++; return v; }
+    if (v) { nrAvoided++; return v; }
     return Expr::maybeThunk(state, env);
 }
 
 
 Value * ExprString::maybeThunk(EvalState & state, Env & env)
 {
-    state.nrAvoided++;
+    nrAvoided++;
     return &v;
 }
 
 Value * ExprInt::maybeThunk(EvalState & state, Env & env)
 {
-    state.nrAvoided++;
+    nrAvoided++;
     return &v;
 }
 
 Value * ExprFloat::maybeThunk(EvalState & state, Env & env)
 {
-    state.nrAvoided++;
+    nrAvoided++;
     return &v;
 }
 
 Value * ExprPath::maybeThunk(EvalState & state, Env & env)
 {
-    state.nrAvoided++;
+    nrAvoided++;
     return &v;
 }
 
@@ -918,7 +914,7 @@ void EvalState::evalFile(const Path & path_, Value & v, bool mustBeTrivial)
         // computation.
         if (mustBeTrivial &&
             !(dynamic_cast<ExprAttrs *>(e)))
-            throw EvalError("file '%s' must be an attribute set", path);
+            throw Error("file '%s' must be an attribute set", path);
         eval(e, v);
     } catch (Error & e) {
         addErrorTrace(e, "while evaluating the file '%1%':", path2);
@@ -1117,66 +1113,235 @@ void ExprVar::eval(EvalState & state, Env & env, Value & v)
     v = *v2;
 }
 
+unsigned long nrLookups = 0;
 
-static string showAttrPath(EvalState & state, Env & env, const AttrPath & attrPath)
+std::pair<ValueCache::CacheResult, ValueCache> ValueCache::getValue(EvalState & state, const std::vector<Symbol> & selector, Value & dest)
 {
-    std::ostringstream out;
-    bool first = true;
-    for (auto & i : attrPath) {
-        if (!first) out << '.'; else first = false;
-        try {
-            out << getName(i, state, env);
-        } catch (Error & e) {
-            assert(!i.symbol.set());
-            out << "\"${" << *i.expr << "}\"";
-        }
-    }
-    return out.str();
+    if (!rawCache)
+        return { {NoCacheKey}, ValueCache(nullptr) };
+    auto resultingCursor = rawCache->findAlongAttrPath(selector);
+    if (!resultingCursor)
+        return { {CacheMiss}, ValueCache(nullptr) };
+
+    auto cachedValue = resultingCursor->getCachedValue();
+    auto cacheResult = std::visit(
+        overloaded{
+            [&](tree_cache::attributeSet_t) { return ValueCache::CacheResult{ Forward }; },
+            [&](tree_cache::unknown_t) { return ValueCache::CacheResult{ UnCacheable }; },
+            [&](tree_cache::thunk_t) { return ValueCache::CacheResult{ CacheMiss }; },
+            [&](tree_cache::failed_t x) -> ValueCache::CacheResult {throw EvalError(x.error); },
+            [&](tree_cache::missing_t x) {
+                return ValueCache::CacheResult{
+                    .returnCode = CacheHit,
+                    .lastQueriedSymbolIfMissing = x.attrName
+                };
+            },
+            [&](tree_cache::string_t s) {
+                PathSet context;
+                for (auto& [pathName, outputName] : s.second) {
+                    // If the cached value depends on some non-existent
+                    // path, we need to discard it and force the evaluation
+                    // to bring back the context in the store
+                    if (!state.store->isValidPath(
+                            state.store->parseStorePath(pathName)))
+                        return ValueCache::CacheResult{UnCacheable};
+                    context.insert("!" + outputName + "!" + pathName);
+                }
+                mkString(dest, s.first, context);
+                return ValueCache::CacheResult{CacheHit};
+            },
+            [&](tree_cache::wrapped_basetype<bool> b) {
+                dest.mkBool(b.value);
+                return ValueCache::CacheResult{CacheHit};
+            },
+            [&](tree_cache::wrapped_basetype<int64_t> i) {
+                dest.mkInt(i.value);
+                return ValueCache::CacheResult{CacheHit};
+            },
+            [&](tree_cache::wrapped_basetype<double> d) {
+                dest.mkFloat(d.value);
+                return ValueCache::CacheResult{CacheHit};
+            },
+        },
+        cachedValue);
+
+    return { cacheResult, ValueCache(resultingCursor) };
 }
 
+void EvalState::updateCacheStats(ValueCache::CacheResult cacheResult)
+{
+    switch (cacheResult.returnCode) {
+        case ValueCache::CacheHit:
+            nrCacheHits++;
+            break;
+        case ValueCache::CacheMiss:
+            nrCacheMisses++;
+            break;
+        case ValueCache::UnCacheable:
+            nrUncacheable++;
+            break;
+        case ValueCache::NoCacheKey:
+            nrUncached++;
+            break;
+        case ValueCache::Forward:
+            nrCacheHits++;
+            break;
+    };
+}
+
+EvalState::LazyValueType EvalState::lazyGetAttrField(Value & attrs, const std::vector<Symbol> & selector, const Pos & pos, Value & dest)
+{
+    auto eval_cache = attrs.getEvalCache();
+    if (eval_cache.isEmpty()) {
+        forceValue(attrs, pos);
+        eval_cache = attrs.getEvalCache();
+    }
+    auto [ cacheResult, resultingCursor ] = eval_cache.getValue(*this, selector, dest);
+    updateCacheStats(cacheResult);
+
+    auto delayValue = [&](ValueCache & cursor) {
+            auto recordAsVar = new ExprCastedVar(&attrs);
+            auto accessExpr = new ExprSelect(pos, recordAsVar, selector);
+            auto thunk = (Thunk*)allocBytes(sizeof(Thunk));
+            thunk->expr = accessExpr;
+            thunk->env = &baseEnv;
+
+            dest.mkCachedThunk(
+                thunk,
+                new ValueCache(cursor)
+            );
+    };
+
+    switch (cacheResult.returnCode) {
+        case ValueCache::CacheHit:
+            if (cacheResult.lastQueriedSymbolIfMissing)
+                return LazyValueType::Missing;
+            return LazyValueType::PlainValue;
+        case ValueCache::UnCacheable:
+            delayValue(resultingCursor);
+            return LazyValueType::DelayedUncacheable;
+        case ValueCache::Forward:
+            delayValue(resultingCursor);
+            return LazyValueType::DelayedAttr;
+        default:
+            if(getAttrField(attrs, selector, pos, dest))
+                return LazyValueType::PlainValue;
+            else
+                return LazyValueType::Missing;
+    }
+
+}
+
+bool EvalState::getAttrField(Value & attrs, const std::vector<Symbol> & selector, const Pos & pos, Value & dest)
+{
+    Pos * pos2 = 0;
+
+    auto eval_cache = attrs.getEvalCache();
+    if (eval_cache.isEmpty()) {
+        forceValue(attrs, pos);
+        eval_cache = attrs.getEvalCache();
+    }
+    auto [ cacheResult, resultingCursor ] = eval_cache.getValue(*this, selector, dest);
+    updateCacheStats(cacheResult);
+    switch (cacheResult.returnCode) {
+        case ValueCache::CacheHit:
+            if (cacheResult.lastQueriedSymbolIfMissing)
+                return false;
+            return true;
+        case ValueCache::CacheMiss:
+            resultingCursor = eval_cache;
+            break;
+        case ValueCache::Forward: // FIXME: Handle properly
+        case ValueCache::NoCacheKey:
+        case ValueCache::UnCacheable:
+            ;
+    }
+
+    forceValue(attrs, pos);
+
+    Value * vAttrs = &attrs;
+    try {
+        for (auto & name : selector) {
+            nrLookups++;
+            Bindings::iterator j;
+            if (vAttrs->type() != nAttrs ||
+                (j = vAttrs->attrs->find(name)) == vAttrs->attrs->end()) {
+                return false;
+            }
+            vAttrs = j->value;
+            pos2 = j->pos;
+            try {
+                forceValue(*vAttrs, pos2 != NULL ? *pos2 : pos );
+            } catch (EvalError & e) {
+                resultingCursor.addFailedChild(name, e);
+                throw;
+            }
+            if (cacheResult.returnCode == ValueCache::CacheMiss) {
+                resultingCursor = resultingCursor.addChild(name, *vAttrs);
+                vAttrs->setEvalCache(resultingCursor);
+            }
+            if (countCalls && pos2) attrSelects[*pos2]++;
+        }
+
+    } catch (Error & e) {
+        if (pos2 && pos2->file != sDerivationNix) {
+            vector<string> strSelector;
+            addErrorTrace(e, *pos2, "while evaluating the attribute '%1%'", concatStringsSep(".", selector));
+        }
+        throw;
+    }
+
+    if (cacheResult.returnCode == ValueCache::Forward)
+        vAttrs->setEvalCache(resultingCursor);
+
+    dest = *vAttrs;
+    return true;
+}
+
+void EvalState::getAttrFieldThrow(Value & attrs, const std::vector<Symbol> & selector, const Pos & pos, Value & dest)
+{
+    if (!getAttrField(attrs, selector, pos, dest))
+        throw Error("Missing attribute path '%s'", "ImTooLazyToImplementThisRightNow");
+}
+
+std::vector<Symbol> EvalState::getFields(Value & attrs, const Pos & pos)
+{
+    auto eval_cache = attrs.getEvalCache();
+    if (eval_cache.isEmpty()) {
+        forceValue(attrs, pos);
+        eval_cache = attrs.getEvalCache();
+    }
+    if (auto attrNames = eval_cache.listChildren(symbols)) {
+        return *attrNames;
+    }
+
+    forceAttrs(attrs);
+    std::vector<Symbol> res;
+    for (auto & attr : *attrs.attrs)
+        res.push_back(attr.name);
+    return res;
+}
 
 void ExprSelect::eval(EvalState & state, Env & env, Value & v)
 {
     Value vTmp;
-    Pos * pos2 = 0;
-    Value * vAttrs = &vTmp;
 
     e->eval(state, env, vTmp);
 
-    try {
+    std::vector<Symbol> selector;
+    for (auto & i : attrPath)
+        selector.push_back(getName(i, state, env));
 
-        for (auto & i : attrPath) {
-            state.nrLookups++;
-            Bindings::iterator j;
-            Symbol name = getName(i, state, env);
-            if (def) {
-                state.forceValue(*vAttrs, pos);
-                if (vAttrs->type() != nAttrs ||
-                    (j = vAttrs->attrs->find(name)) == vAttrs->attrs->end())
-                {
-                    def->eval(state, env, v);
-                    return;
-                }
-            } else {
-                state.forceAttrs(*vAttrs, pos);
-                if ((j = vAttrs->attrs->find(name)) == vAttrs->attrs->end())
-                    throwEvalError(pos, "attribute '%1%' missing", name);
-            }
-            vAttrs = j->value;
-            pos2 = j->pos;
-            if (state.countCalls && pos2) state.attrSelects[*pos2]++;
+    bool gotField = state.getAttrField(vTmp, selector, pos, v);
+    if (!gotField) {
+        if (def) {
+            def->eval(state, env, v);
+            return;
+        } else {
+            throwEvalError(pos, "Missing field");
         }
-
-        state.forceValue(*vAttrs, ( pos2 != NULL ? *pos2 : this->pos ) );
-
-    } catch (Error & e) {
-        if (pos2 && pos2->file != state.sDerivationNix)
-            addErrorTrace(e, *pos2, "while evaluating the attribute '%1%'",
-                showAttrPath(state, env, attrPath));
-        throw;
     }
 
-    v = *vAttrs;
 }
 
 
@@ -1359,9 +1524,38 @@ void EvalState::incrFunctionCall(ExprLambda * fun)
     functionCalls[fun]++;
 }
 
+std::optional<tree_cache::AttrValue> ValueCache::getRawValue()
+{
+    if (!rawCache)
+        return std::nullopt;
+    return rawCache->getCachedValue();
+}
+
+std::optional<std::vector<Symbol>> ValueCache::listChildren(SymbolTable& symbols)
+{
+    auto ret = std::vector<Symbol>();
+    if (rawCache) {
+        auto cachedValue = rawCache->getCachedValue();
+            if (std::get_if<tree_cache::attributeSet_t>(&cachedValue)) {
+                for (auto & fieldStr : rawCache->getChildren())
+                    ret.push_back(symbols.create(fieldStr));
+            }
+            return ret;
+    }
+    return std::nullopt;
+}
 
 void EvalState::autoCallFunction(Bindings & args, Value & fun, Value & res)
 {
+    if (auto evalCache = fun.getEvalCache(); !evalCache.isEmpty()) {
+        if (auto cacheValue = evalCache.getRawValue()) {
+            if (std::holds_alternative<tree_cache::attributeSet_t>(*cacheValue)) {
+                res = fun;
+                return;
+            }
+        }
+    }
+
     forceValue(fun);
 
     if (fun.type() == nAttrs) {
@@ -1707,18 +1901,6 @@ string EvalState::forceString(Value & v, const Pos & pos)
 }
 
 
-/* Decode a context string ‘!<name>!<path>’ into a pair <path,
-   name>. */
-std::pair<string, string> decodeContext(std::string_view s)
-{
-    if (s.at(0) == '!') {
-        size_t index = s.find("!", 1);
-        return {std::string(s.substr(index + 1)), std::string(s.substr(1, index - 1))};
-    } else
-        return {s.at(0) == '/' ? std::string(s) : std::string(s.substr(1)), ""};
-}
-
-
 void copyContext(const Value & v, PathSet & context)
 {
     if (v.string.context)
@@ -1737,6 +1919,102 @@ std::vector<std::pair<Path, std::string>> Value::getContext()
     return res;
 }
 
+ValueCache & Value::getEvalCache()
+{
+    if (internalType == tAttrs) {
+        return attrs->eval_cache;
+    } else if (internalType == tCachedThunk) {
+        return *cachedThunk.cache;
+    } else {
+        return ValueCache::empty;
+    }
+}
+
+ValueCache ValueCache::empty = ValueCache(nullptr);
+
+tree_cache::AttrValue cachedValueFor(Value& v)
+{
+    tree_cache::AttrValue valueToCache;
+    switch (v.type()) {
+        case nThunk:
+            valueToCache = tree_cache::thunk_t{};
+            break;
+        case nNull:
+        case nList:
+        case nFunction:
+        case nExternal:
+            valueToCache = tree_cache::unknown_t{};
+            break;
+        case nBool:
+            valueToCache = tree_cache::wrapped_basetype<bool>{v.boolean};
+            break;
+        case nString:
+            valueToCache = tree_cache::string_t{
+                v.string.s,
+                v.getContext()
+            };
+            break;
+        case nPath:
+            valueToCache = tree_cache::string_t{
+                v.path,
+                {}
+            };
+            break;
+        case nAttrs:
+            valueToCache = tree_cache::attributeSet_t{};
+            break;
+        case nInt:
+            valueToCache = tree_cache::wrapped_basetype<int64_t>{v.integer};
+            break;
+        case nFloat:
+            valueToCache = tree_cache::wrapped_basetype<double>{v.fpoint};
+            break;
+    };
+    return valueToCache;
+}
+
+ValueCache ValueCache::addChild(const Symbol& name, Value& value)
+{
+    if (!rawCache)
+        return ValueCache::empty;
+
+    auto cachedValue = cachedValueFor(value);
+    auto ret = ValueCache(rawCache->addChild(name, cachedValue));
+    if (value.type() == nAttrs)
+        ret.addAttrSetChilds(*value.attrs);
+    return ret;
+}
+
+
+ValueCache ValueCache::addFailedChild(const Symbol& name, const Error & error)
+{
+    if (!rawCache) return ValueCache::empty;
+    return ValueCache(rawCache->addChild(name, tree_cache::failed_t{ .error = error.msg() }));
+}
+
+void ValueCache::addAttrSetChilds(Bindings & children)
+{
+    if (!rawCache) return;
+    for (auto & attr : children) {
+        // We could in theory directly store the value, but that would cause
+        // an infinite recursion in case of a cyclic attrset.
+        // So in a first time, just store a thunk
+        if (attr.value->type() == nAttrs)
+            rawCache->addChild(attr.name, tree_cache::thunk_t{});
+        else
+            addChild(attr.name, *attr.value);
+    }
+
+}
+
+void Value::setEvalCache(ValueCache & newCache)
+{
+    if (internalType == tAttrs) {
+        attrs->eval_cache = newCache;
+    } else if (internalType == tCachedThunk) {
+        cachedThunk.cache = &newCache;
+    }
+}
 
 string EvalState::forceString(Value & v, PathSet & context, const Pos & pos)
 {
@@ -2019,6 +2297,13 @@ void EvalState::printStats()
         topObj.attr("nrLookups", nrLookups);
         topObj.attr("nrPrimOpCalls", nrPrimOpCalls);
         topObj.attr("nrFunctionCalls", nrFunctionCalls);
+        {
+            auto cache = topObj.object("evalCache");
+            cache.attr("nrCacheMisses", nrCacheMisses);
+            cache.attr("nrCacheHits", nrCacheHits);
+            cache.attr("nrUncached", nrUncached);
+            cache.attr("nrUncacheable", nrUncacheable);
+        }
 #if HAVE_BOEHMGC
         {
             auto gc = topObj.object("gc");
@@ -2119,6 +2404,21 @@ Strings EvalSettings::getDefaultNixPath()
     return res;
 }
 
+std::shared_ptr<tree_cache::Cache> EvalState::openTreeCache(Hash cacheKey)
+{
+    if (auto iter = evalCache.find(cacheKey); iter != evalCache.end())
+        return iter->second;
+
+    if (!(evalSettings.useEvalCache && evalSettings.pureEval))
+        return nullptr;
+    auto thisCache = tree_cache::Cache::tryCreate(
+            cacheKey,
+            symbols
+    );
+    evalCache.insert({cacheKey, thisCache});
+    return thisCache;
+}
+
 EvalSettings evalSettings;
 
 static GlobalConfig::Register rEvalSettings(&evalSettings);

src/libexpr/eval.hh

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "attr-set.hh"
+#include "context.hh"
 #include "value.hh"
 #include "nixexpr.hh"
 #include "symbol-table.hh"
@@ -94,12 +95,8 @@ public:
 
     Value vEmptySet;
 
-    /* Store used to materialise .drv files. */
     const ref<Store> store;
 
-    /* Store used to build stuff. */
-    const ref<Store> buildStore;
-
 
 private:
     SrcToStore srcToStore;
@@ -119,6 +116,7 @@ private:
     typedef std::map<Path, Value> FileEvalCache;
 #endif
     FileEvalCache fileEvalCache;
+    std::map<Hash, std::shared_ptr<tree_cache::Cache>> evalCache;
 
     SearchPath searchPath;
 
@@ -132,12 +130,11 @@ private:
 
 public:
 
-    EvalState(
-        const Strings & _searchPath,
-        ref<Store> store,
-        std::shared_ptr<Store> buildStore = nullptr);
+    EvalState(const Strings & _searchPath, ref<Store> store);
     ~EvalState();
 
+    std::shared_ptr<tree_cache::Cache> openTreeCache(Hash);
+
     void addToSearchPath(const string & s);
 
     SearchPath getSearchPath() { return searchPath; }
@@ -317,21 +314,25 @@ public:
 
     void realiseContext(const PathSet & context);
 
+    void updateCacheStats(ValueCache::CacheResult);
+
 private:
 
     unsigned long nrEnvs = 0;
     unsigned long nrValuesInEnvs = 0;
     unsigned long nrValues = 0;
     unsigned long nrListElems = 0;
-    unsigned long nrLookups = 0;
     unsigned long nrAttrsets = 0;
     unsigned long nrAttrsInAttrsets = 0;
-    unsigned long nrAvoided = 0;
     unsigned long nrOpUpdates = 0;
     unsigned long nrOpUpdateValuesCopied = 0;
     unsigned long nrListConcats = 0;
     unsigned long nrPrimOpCalls = 0;
     unsigned long nrFunctionCalls = 0;
+    unsigned long nrCacheHits = 0;
+    unsigned long nrCacheMisses = 0;
+    unsigned long nrUncacheable = 0;
+    unsigned long nrUncached = 0;
 
     bool countCalls;
 
@@ -348,14 +349,30 @@ private:
 
     friend struct ExprOpUpdate;
     friend struct ExprOpConcatLists;
-    friend struct ExprVar;
-    friend struct ExprString;
-    friend struct ExprInt;
-    friend struct ExprFloat;
-    friend struct ExprPath;
     friend struct ExprSelect;
     friend void prim_getAttr(EvalState & state, const Pos & pos, Value * * args, Value & v);
     friend void prim_match(EvalState & state, const Pos & pos, Value * * args, Value & v);
+
+public:
+
+    bool getAttrField(Value & attrs, const std::vector<Symbol> & selector, const Pos & pos, Value & dest);
+
+    enum struct LazyValueType {
+        PlainValue,
+        DelayedUncacheable,
+        DelayedAttr,
+        Missing,
+    };
+
+    // Similar to `getAttrField`, but if the cache says that the result is an
+    // attribute set, just return a thunk to it rather than forcing it.
+    LazyValueType lazyGetAttrField(Value & attrs, const std::vector<Symbol> & selector, const Pos & pos, Value & dest);
+
+    // Similar to `getAttrField`, but throws an `Error` if the field can’t be
+    // found
+    void getAttrFieldThrow(Value & attrs, const std::vector<Symbol> & selector, const Pos & pos, Value & dest);
+
+    std::vector<Symbol> getFields(Value & attrs, const Pos & pos);
 };
 
 
@@ -363,10 +380,6 @@ private:
 string showType(ValueType type);
 string showType(const Value & v);
 
-/* Decode a context string ‘!<name>!<path>’ into a pair <path,
-   name>. */
-std::pair<string, string> decodeContext(std::string_view s);
-
 /* If `path' refers to a directory, then append "/default.nix". */
 Path resolveExprPath(Path path);
 

src/libexpr/flake/config.cc

@@ -29,7 +29,7 @@ static void writeTrustedList(const TrustedList & trustedList)
 
 void ConfigFile::apply()
 {
-    std::set<std::string> whitelist{"bash-prompt", "bash-prompt-suffix", "flake-registry"};
+    std::set<std::string> whitelist{"bash-prompt", "bash-prompt-suffix"};
 
     for (auto & [name, value] : settings) {
 

src/libexpr/flake/flake.cc

@@ -1,5 +1,4 @@
 #include "flake.hh"
-#include "eval.hh"
 #include "lockfile.hh"
 #include "primops.hh"
 #include "eval-inline.hh"
@@ -297,14 +296,7 @@ LockedFlake lockFlake(
 
     FlakeCache flakeCache;
 
-    auto useRegistries = lockFlags.useRegistries.value_or(settings.useRegistries);
-
-    auto flake = getFlake(state, topRef, useRegistries, flakeCache);
-
-    if (lockFlags.applyNixConfig) {
-        flake.config.apply();
-        // FIXME: send new config to the daemon.
-    }
+    auto flake = getFlake(state, topRef, lockFlags.useRegistries, flakeCache);
 
     try {
 
@@ -367,12 +359,7 @@ LockedFlake lockFlake(
                        ancestors? */
                     auto i = overrides.find(inputPath);
                     bool hasOverride = i != overrides.end();
-                    if (hasOverride) {
-                        overridesUsed.insert(inputPath);
-                        // Respect the “flakeness” of the input even if we
-                        // override it
-                        i->second.isFlake = input2.isFlake;
-                    }
+                    if (hasOverride) overridesUsed.insert(inputPath);
                     auto & input = hasOverride ? i->second : input2;
 
                     /* Resolve 'follows' later (since it may refer to an input
@@ -467,7 +454,7 @@ LockedFlake lockFlake(
                             throw Error("cannot update flake input '%s' in pure mode", inputPathS);
 
                         if (input.isFlake) {
-                            auto inputFlake = getFlake(state, *input.ref, useRegistries, flakeCache);
+                            auto inputFlake = getFlake(state, *input.ref, lockFlags.useRegistries, flakeCache);
 
                             /* Note: in case of an --override-input, we use
                                the *original* ref (input2.ref) for the
@@ -502,7 +489,7 @@ LockedFlake lockFlake(
 
                         else {
                             auto [sourceInfo, resolvedRef, lockedRef] = fetchOrSubstituteTree(
-                                state, *input.ref, useRegistries, flakeCache);
+                                state, *input.ref, lockFlags.useRegistries, flakeCache);
                             node->inputs.insert_or_assign(id,
                                 std::make_shared<LockedNode>(lockedRef, *input.ref, false));
                         }
@@ -567,8 +554,8 @@ LockedFlake lockFlake(
                         topRef.input.markChangedFile(
                             (topRef.subdir == "" ? "" : topRef.subdir + "/") + "flake.lock",
                             lockFlags.commitLockFile
-                            ? std::optional<std::string>(fmt("%s: %s\n\nFlake lock file changes:\n\n%s",
-                                    relPath, lockFileExists ? "Update" : "Add", filterANSIEscapes(diff, true)))
+                            ? std::optional<std::string>(fmt("%s: %s\n\nFlake input changes:\n\n%s",
+                                    relPath, lockFileExists ? "Update" : "Add", diff))
                             : std::nullopt);
 
                         /* Rewriting the lockfile changed the top-level
@@ -576,7 +563,7 @@ LockedFlake lockFlake(
                            also just clear the 'rev' field... */
                         auto prevLockedRef = flake.lockedRef;
                         FlakeCache dummyCache;
-                        flake = getFlake(state, topRef, useRegistries, dummyCache);
+                        flake = getFlake(state, topRef, lockFlags.useRegistries, dummyCache);
 
                         if (lockFlags.commitLockFile &&
                             flake.lockedRef.input.getRev() &&
@@ -609,30 +596,44 @@ void callFlake(EvalState & state,
     const LockedFlake & lockedFlake,
     Value & vRes)
 {
-    auto vLocks = state.allocValue();
+    auto lockExpr = new ExprString(
+        state.symbols.create(lockedFlake.lockFile.to_string())
+    );
+    auto subdirExpr = new ExprString(
+        state.symbols.create(lockedFlake.flake.lockedRef.subdir)
+    );
+
     auto vRootSrc = state.allocValue();
-    auto vRootSubdir = state.allocValue();
-    auto vTmp1 = state.allocValue();
-    auto vTmp2 = state.allocValue();
-
-    mkString(*vLocks, lockedFlake.lockFile.to_string());
-
     emitTreeAttrs(state, *lockedFlake.flake.sourceInfo, lockedFlake.flake.lockedRef.input, *vRootSrc);
 
-    mkString(*vRootSubdir, lockedFlake.flake.lockedRef.subdir);
-
-    static RootValue vCallFlake = nullptr;
-
-    if (!vCallFlake) {
-        vCallFlake = allocRootValue(state.allocValue());
-        state.eval(state.parseExprFromString(
+    static Expr * callFlakeExpr = nullptr;
+    if (!callFlakeExpr) {
+        callFlakeExpr = state.parseExprFromString(
             #include "call-flake.nix.gen.hh"
-            , "/"), **vCallFlake);
+            , "/");
     }
 
-    state.callFunction(**vCallFlake, *vLocks, *vTmp1, noPos);
-    state.callFunction(*vTmp1, *vRootSrc, *vTmp2, noPos);
-    state.callFunction(*vTmp2, *vRootSubdir, vRes, noPos);
+    auto resExpr = new ExprApp(
+        new ExprApp(
+            new ExprApp(
+                callFlakeExpr,
+                lockExpr
+            ),
+            new ExprCastedVar(vRootSrc)
+        ),
+        subdirExpr
+    );
+    auto thunk = (Thunk*)allocBytes(sizeof(Thunk));
+    thunk->expr = resExpr;
+    thunk->env = &state.baseEnv;
+    auto fingerprint = lockedFlake.getFingerprint();
+    auto treeCache = state.openTreeCache(fingerprint);
+    auto cacheRoot = treeCache ? treeCache->getRoot() : nullptr;
+    auto evalCache = new ValueCache(cacheRoot);
+    vRes.mkCachedThunk(
+        thunk,
+        evalCache
+    );
 }
 
 static void prim_getFlake(EvalState & state, const Pos & pos, Value * * args, Value & v)
@@ -646,7 +647,7 @@ static void prim_getFlake(EvalState & state, const Pos & pos, Value * * args, Va
         lockFlake(state, flakeRef,
             LockFlags {
                 .updateLockFile = false,
-                .useRegistries = !evalSettings.pureEval && !settings.useRegistries,
+                .useRegistries = !evalSettings.pureEval,
                 .allowMutable  = !evalSettings.pureEval,
             }),
         v);

src/libexpr/flake/flake.hh

@@ -102,11 +102,7 @@ struct LockFlags
 
     /* Whether to use the registries to lookup indirect flake
        references like 'nixpkgs'. */
-    std::optional<bool> useRegistries = std::nullopt;
-
-    /* Whether to apply flake's nixConfig attribute to the configuration */
-
-    bool applyNixConfig = false;
+    bool useRegistries = true;
 
     /* Whether mutable flake references (i.e. those without a Git
        revision or similar) without a corresponding lock are

src/libexpr/flake/lockfile.cc

@@ -2,8 +2,6 @@
 #include "store-api.hh"
 #include "url-parts.hh"
 
-#include <iomanip>
-
 #include <nlohmann/json.hpp>
 
 namespace nix::flake {
@@ -270,20 +268,10 @@ std::map<InputPath, Node::Edge> LockFile::getAllInputs() const
     return res;
 }
 
-static std::string describe(const FlakeRef & flakeRef)
-{
-    auto s = fmt("'%s'", flakeRef.to_string());
-
-    if (auto lastModified = flakeRef.input.getLastModified())
-        s += fmt(" (%s)", std::put_time(std::gmtime(&*lastModified), "%Y-%m-%d"));
-
-    return s;
-}
-
 std::ostream & operator <<(std::ostream & stream, const Node::Edge & edge)
 {
     if (auto node = std::get_if<0>(&edge))
-        stream << describe((*node)->lockedRef);
+        stream << "'" << (*node)->lockedRef << "'";
     else if (auto follows = std::get_if<1>(&edge))
         stream << fmt("follows '%s'", printInputPath(*follows));
     return stream;
@@ -311,15 +299,14 @@ std::string LockFile::diff(const LockFile & oldLocks, const LockFile & newLocks)
 
     while (i != oldFlat.end() || j != newFlat.end()) {
         if (j != newFlat.end() && (i == oldFlat.end() || i->first > j->first)) {
-            res += fmt("• " ANSI_GREEN "Added input '%s':" ANSI_NORMAL "\n    %s\n",
-                printInputPath(j->first), j->second);
+            res += fmt("* Added '%s': %s\n", printInputPath(j->first), j->second);
             ++j;
         } else if (i != oldFlat.end() && (j == newFlat.end() || i->first < j->first)) {
-            res += fmt("• " ANSI_RED "Removed input '%s'" ANSI_NORMAL "\n", printInputPath(i->first));
+            res += fmt("* Removed '%s'\n", printInputPath(i->first));
             ++i;
         } else {
             if (!equals(i->second, j->second)) {
-                res += fmt("• " ANSI_BOLD "Updated input '%s':" ANSI_NORMAL "\n    %s\n  → %s\n",
+                res += fmt("* Updated '%s': %s -> %s\n",
                     printInputPath(i->first),
                     i->second,
                     j->second);

src/libexpr/lexer.l

@@ -38,13 +38,11 @@ static void adjustLoc(YYLTYPE * loc, const char * s, size_t len)
     loc->first_line = loc->last_line;
     loc->first_column = loc->last_column;
 
-    for (size_t i = 0; i < len; i++) {
+    while (len--) {
        switch (*s++) {
        case '\r':
-           if (*s == '\n') { /* cr/lf */
-               i++;
+           if (*s == '\n') /* cr/lf */
                s++;
-           }
            /* fall through */
        case '\n':
            ++loc->last_line;

src/libexpr/local.mk

@@ -15,8 +15,8 @@ libexpr_CXXFLAGS += -I src/libutil -I src/libstore -I src/libfetchers -I src/lib
 
 libexpr_LIBS = libutil libstore libfetchers
 
-libexpr_LDFLAGS = -lboost_context -pthread
-ifdef HOST_LINUX
+libexpr_LDFLAGS = -lboost_context
+ifeq ($(OS), Linux)
  libexpr_LDFLAGS += -ldl
 endif
 
@@ -35,7 +35,7 @@ $(d)/lexer-tab.cc $(d)/lexer-tab.hh: $(d)/lexer.l
 
 clean-files += $(d)/parser-tab.cc $(d)/parser-tab.hh $(d)/lexer-tab.cc $(d)/lexer-tab.hh
 
-$(eval $(call install-file-in, $(d)/nix-expr.pc, $(libdir)/pkgconfig, 0644))
+$(eval $(call install-file-in, $(d)/nix-expr.pc, $(prefix)/lib/pkgconfig, 0644))
 
 $(foreach i, $(wildcard src/libexpr/flake/*.hh), \
   $(eval $(call install-file-in, $(i), $(includedir)/nix/flake, 0644)))

src/libexpr/nixexpr.cc

@@ -440,6 +440,18 @@ string ExprLambda::showNamePos() const
     return (format("%1% at %2%") % (name.set() ? "'" + (string) name + "'" : "anonymous function") % pos).str();
 }
 
+void ExprCastedVar::show(std::ostream & str) const {
+    std::set<const Value*> active;
+    printValue(str, active, *v);
+}
+
+void ExprCastedVar::bindVars(const StaticEnv & env) {}
+void ExprCastedVar::eval(EvalState & state, Env & env, Value & v) {
+    v = std::move(*this->v);
+}
+Value * ExprCastedVar::maybeThunk(EvalState & state, Env & env) {
+    return v;
+}
 
 
 /* Symbol table. */

src/libexpr/nixexpr.hh

@@ -165,7 +165,12 @@ struct ExprSelect : Expr
     Expr * e, * def;
     AttrPath attrPath;
     ExprSelect(const Pos & pos, Expr * e, const AttrPath & attrPath, Expr * def) : pos(pos), e(e), def(def), attrPath(attrPath) { };
-    ExprSelect(const Pos & pos, Expr * e, const Symbol & name) : pos(pos), e(e), def(0) { attrPath.push_back(AttrName(name)); };
+    ExprSelect(const Pos & pos, Expr * e, const Symbol & name)
+        : ExprSelect(pos, e, std::vector{name}) {};
+    ExprSelect(const Pos & pos, Expr * e, const std::vector<Symbol> & symbolicAttrPath) : pos(pos), e(e), def(0) {
+        for (auto & name : symbolicAttrPath)
+            attrPath.push_back(AttrName(name));
+    };
     COMMON_METHODS
 };
 
@@ -334,6 +339,14 @@ struct ExprPos : Expr
     COMMON_METHODS
 };
 
+struct ExprCastedVar : Expr
+{
+    Value * v;
+    ExprCastedVar(Value * v) : v(v) {};
+    Value * maybeThunk(EvalState & state, Env & env);
+    COMMON_METHODS
+};
+
 
 /* Static environments are used to map variable names onto (level,
    displacement) pairs used to obtain the value of the variable at

src/libexpr/primops.cc

@@ -3109,7 +3109,7 @@ static RegisterPrimOp primop_toString({
 
         - A path (e.g., `toString /foo/bar` yields `"/foo/bar"`.
 
-        - A set containing `{ __toString = self: ...; }` or `{ outPath = ...; }`.
+        - A set containing `{ __toString = self: ...; }`.
 
         - An integer.
 
@@ -3645,7 +3645,9 @@ void EvalState::createBaseEnv()
     if (!evalSettings.pureEval) {
         mkInt(v, time(0));
         addConstant("__currentTime", v);
+    }
 
+    if (!evalSettings.pureEval) {
         mkString(v, settings.thisSystem.get());
         addConstant("__currentSystem", v);
     }

src/libexpr/primops/fetchMercurial.cc

@@ -62,7 +62,6 @@ static void prim_fetchMercurial(EvalState & state, const Pos & pos, Value * * ar
     fetchers::Attrs attrs;
     attrs.insert_or_assign("type", "hg");
     attrs.insert_or_assign("url", url.find("://") != std::string::npos ? url : "file://" + url);
-    attrs.insert_or_assign("name", name);
     if (ref) attrs.insert_or_assign("ref", *ref);
     if (rev) attrs.insert_or_assign("rev", rev->gitRev());
     auto input = fetchers::Input::fromAttrs(std::move(attrs));

src/libexpr/primops/fetchTree.cc

@@ -7,7 +7,6 @@
 
 #include <ctime>
 #include <iomanip>
-#include <regex>
 
 namespace nix {
 
@@ -61,19 +60,10 @@ void emitTreeAttrs(
     v.attrs->sort();
 }
 
-std::string fixURI(std::string uri, EvalState &state, const std::string & defaultScheme = "file")
+std::string fixURI(std::string uri, EvalState &state)
 {
     state.checkURI(uri);
-    return uri.find("://") != std::string::npos ? uri : defaultScheme + "://" + uri;
-}
-
-std::string fixURIForGit(std::string uri, EvalState & state)
-{
-    static std::regex scp_uri("([^/].*)@(.*):(.*)");
-    if (uri[0] != '/' && std::regex_match(uri, scp_uri))
-        return fixURI(std::regex_replace(uri, scp_uri, "$1@$2/$3"), state, "ssh");
-    else
-        return fixURI(uri, state);
+    return uri.find("://") != std::string::npos ? uri : "file://" + uri;
 }
 
 void addURI(EvalState &state, fetchers::Attrs &attrs, Symbol name, std::string v)
@@ -82,18 +72,13 @@ void addURI(EvalState &state, fetchers::Attrs &attrs, Symbol name, std::string v
     attrs.emplace(name, n == "url" ? fixURI(v, state) : v);
 }
 
-struct FetchTreeParams {
-    bool emptyRevFallback = false;
-    bool allowNameArgument = false;
-};
-
 static void fetchTree(
     EvalState &state,
     const Pos &pos,
     Value **args,
     Value &v,
     const std::optional<std::string> type,
-    const FetchTreeParams & params = FetchTreeParams{}
+    bool emptyRevFallback = false
 ) {
     fetchers::Input input;
     PathSet context;
@@ -134,25 +119,17 @@ static void fetchTree(
                 .errPos = pos
             });
 
-        if (!params.allowNameArgument)
-            if (auto nameIter = attrs.find("name"); nameIter != attrs.end())
-                throw Error({
-                    .msg = hintfmt("attribute 'name' isn’t supported in call to 'fetchTree'"),
-                    .errPos = pos
-                });
-
-
         input = fetchers::Input::fromAttrs(std::move(attrs));
     } else {
-        auto url = state.coerceToString(pos, *args[0], context, false, false);
+        auto url = fixURI(state.coerceToString(pos, *args[0], context, false, false), state);
 
         if (type == "git") {
             fetchers::Attrs attrs;
             attrs.emplace("type", "git");
-            attrs.emplace("url", fixURIForGit(url, state));
+            attrs.emplace("url", url);
             input = fetchers::Input::fromAttrs(std::move(attrs));
         } else {
-            input = fetchers::Input::fromURL(fixURI(url, state));
+            input = fetchers::Input::fromURL(url);
         }
     }
 
@@ -167,13 +144,13 @@ static void fetchTree(
     if (state.allowedPaths)
         state.allowedPaths->insert(tree.actualPath);
 
-    emitTreeAttrs(state, tree, input2, v, params.emptyRevFallback);
+    emitTreeAttrs(state, tree, input2, v, emptyRevFallback);
 }
 
 static void prim_fetchTree(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
     settings.requireExperimentalFeature("flakes");
-    fetchTree(state, pos, args, v, std::nullopt, FetchTreeParams { .allowNameArgument = false });
+    fetchTree(state, pos, args, v, std::nullopt);
 }
 
 // FIXME: document
@@ -315,7 +292,7 @@ static RegisterPrimOp primop_fetchTarball({
 
 static void prim_fetchGit(EvalState &state, const Pos &pos, Value **args, Value &v)
 {
-    fetchTree(state, pos, args, v, "git", FetchTreeParams { .emptyRevFallback = true, .allowNameArgument = true });
+    fetchTree(state, pos, args, v, "git", true);
 }
 
 static RegisterPrimOp primop_fetchGit({

src/libexpr/tree-cache.cc

@@ -0,0 +1,392 @@
+#include "tree-cache.hh"
+#include "sqlite.hh"
+#include "store-api.hh"
+#include "context.hh"
+
+namespace nix::tree_cache {
+
+static const char * schema = R"sql(
+create table if not exists Attributes (
+    id          integer primary key autoincrement not null,
+    parent      integer not null,
+    name        text,
+    type        integer not null,
+    value       text,
+    context     text,
+    unique      (parent, name)
+);
+
+create index if not exists IndexByParent on Attributes(parent, name);
+)sql";
+
+struct AttrDb
+{
+    std::atomic_bool failed{false};
+
+    struct State
+    {
+        SQLite db;
+        SQLiteStmt insertAttribute;
+        SQLiteStmt updateAttribute;
+        SQLiteStmt insertAttributeWithContext;
+        SQLiteStmt queryAttribute;
+        SQLiteStmt queryAttributes;
+        std::unique_ptr<SQLiteTxn> txn;
+    };
+
+    std::unique_ptr<Sync<State>> _state;
+
+    AttrDb(const Hash & fingerprint)
+        : _state(std::make_unique<Sync<State>>())
+    {
+        auto state(_state->lock());
+
+        Path cacheDir = getCacheDir() + "/nix/eval-cache-v3";
+        createDirs(cacheDir);
+
+        Path dbPath = cacheDir + "/" + fingerprint.to_string(Base16, false) + ".sqlite";
+
+        state->db = SQLite(dbPath);
+        state->db.isCache();
+        state->db.exec(schema);
+
+        state->insertAttribute.create(state->db,
+            "insert into Attributes(parent, name, type, value) values (?, ?, ?, ?)");
+
+        state->updateAttribute.create(state->db,
+            "update Attributes set type = ?, value = ?, context = ? where id = ?");
+
+        state->insertAttributeWithContext.create(state->db,
+            "insert into Attributes(parent, name, type, value, context) values (?, ?, ?, ?, ?)");
+
+        state->queryAttribute.create(state->db,
+            "select id, type, value, context from Attributes where parent = ? and name = ?");
+
+        state->queryAttributes.create(state->db,
+            "select name, type from Attributes where parent = ?");
+
+        state->txn = std::make_unique<SQLiteTxn>(state->db);
+    }
+
+    ~AttrDb()
+    {
+        try {
+            auto state(_state->lock());
+            if (!failed)
+                state->txn->commit();
+            state->txn.reset();
+        } catch (...) {
+            ignoreException();
+        }
+    }
+
+    template<typename F>
+    AttrId doSQLite(F && fun)
+    {
+        if (failed) return 0;
+        try {
+            return fun();
+        } catch (SQLiteError &) {
+            ignoreException();
+            failed = true;
+            return 0;
+        }
+    }
+
+    /**
+     * Store a leaf of the tree in the db
+     */
+    AttrId addEntry(
+        const AttrKey & key,
+        const AttrValue & value)
+    {
+        return doSQLite([&]()
+        {
+            auto state(_state->lock());
+            auto rawValue = RawValue::fromVariant(value);
+
+            state->insertAttributeWithContext.use()
+                (key.first)
+                (key.second)
+                (rawValue.type)
+                (rawValue.value.value_or(""), rawValue.value.has_value())
+                (rawValue.serializeContext())
+                .exec();
+            AttrId rowId = state->db.getLastInsertedRowId();
+            assert(rowId);
+            return rowId;
+        });
+    }
+
+    std::optional<AttrId> getId(const AttrKey& key)
+    {
+        auto state(_state->lock());
+
+        auto queryAttribute(state->queryAttribute.use()(key.first)(key.second));
+        if (!queryAttribute.next()) return std::nullopt;
+
+        return (AttrType) queryAttribute.getInt(0);
+    }
+
+    AttrId setOrUpdate(const AttrKey& key, const AttrValue& value)
+    {
+        debug("cache: miss for the attribute %s", key.second);
+        if (auto existingId = getId(key)) {
+            setValue(*existingId, value);
+            return *existingId;
+        }
+        return addEntry(key, value);
+    }
+
+    void setValue(const AttrId & id, const AttrValue & value)
+    {
+        auto state(_state->lock());
+            auto rawValue = RawValue::fromVariant(value);
+
+            state->updateAttribute.use()
+                (rawValue.type)
+                (rawValue.value.value_or(""), rawValue.value.has_value())
+                (rawValue.serializeContext())
+                (id)
+                .exec();
+    }
+
+    std::optional<std::pair<AttrId, AttrValue>> getValue(AttrKey key)
+    {
+        auto state(_state->lock());
+
+        auto queryAttribute(state->queryAttribute.use()(key.first)(key.second));
+        if (!queryAttribute.next()) return {};
+
+        auto rowId = (AttrType) queryAttribute.getInt(0);
+        auto type = (AttrType) queryAttribute.getInt(1);
+
+        switch (type) {
+            case AttrType::Attrs: {
+                return {{rowId, attributeSet_t()}};
+            }
+            case AttrType::String: {
+                std::vector<std::pair<Path, std::string>> context;
+                if (!queryAttribute.isNull(3))
+                    for (auto & s : tokenizeString<std::vector<std::string>>(queryAttribute.getStr(3), ";"))
+                        context.push_back(decodeContext(s));
+                return {{rowId, string_t{queryAttribute.getStr(2), context}}};
+            }
+            case AttrType::Bool:
+                return {{rowId, wrapped_basetype<bool>{queryAttribute.getInt(2) != 0}}};
+            case AttrType::Int:
+                return {{rowId, wrapped_basetype<int64_t>{queryAttribute.getInt(2)}}};
+            case AttrType::Double:
+                return {{rowId, wrapped_basetype<double>{(double)queryAttribute.getInt(2)}}};
+            case AttrType::Unknown:
+                return {{rowId, unknown_t{}}};
+            case AttrType::Thunk:
+                return {{rowId, thunk_t{}}};
+            case AttrType::Missing:
+                return {{rowId, missing_t{key.second}}};
+            case AttrType::Failed:
+                return {{rowId, failed_t{queryAttribute.getStr(2)}}};
+            default:
+                throw Error("unexpected type in evaluation cache");
+        }
+    }
+
+    std::vector<std::string> getChildren(AttrId parentId)
+    {
+        std::vector<std::string> res;
+        auto state(_state->lock());
+
+        auto queryAttributes(state->queryAttributes.use()(parentId));
+
+        while (queryAttributes.next()) {
+            if (queryAttributes.getInt(1) != AttrType::Missing)
+            res.push_back(queryAttributes.getStr(0));
+        }
+
+        return res;
+    }
+};
+
+Cache::Cache(const Hash & useCache,
+        SymbolTable & symbols)
+    : db(std::make_shared<AttrDb>(useCache))
+    , symbols(symbols)
+    , rootSymbol(symbols.create("%root%"))
+{
+}
+
+std::shared_ptr<Cache> Cache::tryCreate(const Hash & useCache, SymbolTable & symbols)
+{
+    try {
+        return std::make_shared<Cache>(useCache, symbols);
+    } catch (SQLiteError &) {
+        ignoreException();
+        return nullptr;
+    }
+}
+
+void Cache::commit()
+{
+    if (db) {
+        debug("Saving the cache");
+        auto state(db->_state->lock());
+        if (state->txn->active) {
+            state->txn->commit();
+            state->txn.reset();
+            state->txn = std::make_unique<SQLiteTxn>(state->db);
+        }
+    }
+}
+
+Cursor::Ref Cache::getRoot()
+{
+    return new Cursor(ref(shared_from_this()), std::nullopt, thunk_t{});
+}
+
+Cursor::Cursor(
+    ref<Cache> root,
+    const Parent & parent,
+    const AttrValue& value
+    )
+    : root(root)
+    , parentId(parent ? std::optional{parent->first.cachedValue.first} : std::nullopt)
+    , label(parent ? parent->second : root->rootSymbol)
+    , cachedValue({root->db->setOrUpdate(getKey(), value), value})
+{
+}
+
+Cursor::Cursor(
+    ref<Cache> root,
+    const Parent & parent,
+    const AttrId & id,
+    const AttrValue & value
+    )
+    : root(root)
+    , parentId(parent ? std::optional{parent->first.cachedValue.first} : std::nullopt)
+    , label(parent ? parent->second : root->rootSymbol)
+    , cachedValue({id, value})
+{
+}
+
+
+AttrKey Cursor::getKey()
+{
+    if (!parentId)
+        return {0, root->rootSymbol};
+    return {*parentId, label};
+}
+
+AttrValue Cursor::getCachedValue()
+{
+    return cachedValue.second;
+}
+
+void Cursor::setValue(const AttrValue & v)
+{
+    root->db->setValue(cachedValue.first, v);
+    cachedValue.second = v;
+}
+
+Cursor::Ref Cursor::addChild(const Symbol & attrPath, const AttrValue & v)
+{
+    Parent parent = {{*this, attrPath}};
+    auto childCursor = new Cursor(
+        root,
+        parent,
+        v
+    );
+    return childCursor;
+}
+
+std::vector<std::string> Cursor::getChildren()
+{
+    return root->db->getChildren(cachedValue.first);
+}
+
+std::optional<std::vector<std::string>> Cursor::getChildrenAtPath(const std::vector<Symbol> & attrPath)
+{
+    auto cursorAtPath = findAlongAttrPath(attrPath);
+    if (cursorAtPath)
+        return cursorAtPath->getChildren();
+    return std::nullopt;
+}
+
+Cursor::Ref Cursor::maybeGetAttr(const Symbol & name)
+{
+    auto rawAttr = root->db->getValue({cachedValue.first, name});
+    if (rawAttr) {
+        Parent parent = {{*this, name}};
+        debug("cache: hit for the attribute %s", cachedValue.first);
+        return new Cursor (
+            root, parent, rawAttr->first,
+            rawAttr->second);
+    }
+    if (std::holds_alternative<attributeSet_t>(cachedValue.second)) {
+        // If the parent is an attribute set but we're not present in the db,
+        // then we're not a member of this attribute set. So mark as missing
+        return addChild(name, missing_t{name});
+    }
+    return nullptr;
+}
+
+Cursor::Ref Cursor::findAlongAttrPath(const std::vector<Symbol> & attrPath)
+{
+    auto currentCursor = this;
+    for (auto & currentAccessor : attrPath) {
+        currentCursor = currentCursor->maybeGetAttr(currentAccessor);
+        if (!currentCursor)
+            break;
+        if (std::holds_alternative<missing_t>(currentCursor->cachedValue.second))
+            break;
+        if (std::holds_alternative<failed_t>(currentCursor->cachedValue.second))
+            break;
+    }
+    return currentCursor;
+}
+
+const RawValue RawValue::fromVariant(const AttrValue & value)
+{
+    RawValue res;
+    std::visit(overloaded{
+      [&](attributeSet_t x) { res.type = AttrType::Attrs; },
+      [&](string_t x) {
+        res.type = AttrType::String;
+        res.value = x.first;
+        res.context = x.second;
+      },
+      [&](wrapped_basetype<bool> x) {
+        res.type = AttrType::Bool;
+        res.value = x.value ? "1" : "0";
+      },
+      [&](wrapped_basetype<int64_t> x) {
+        res.type = AttrType::Int;
+        res.value = std::to_string(x.value);
+      },
+      [&](wrapped_basetype<double> x) {
+        res.type = AttrType::Double;
+        res.value = std::to_string(x.value);
+      },
+      [&](unknown_t x) { res.type = AttrType::Unknown; },
+      [&](missing_t x) { res.type = AttrType::Missing; },
+      [&](thunk_t x) { res.type = AttrType::Thunk; },
+      [&](failed_t x) {
+          res.type = AttrType::Failed;
+          res.value = x.error;
+      }
+    }, value);
+    return res;
+}
+
+std::string RawValue::serializeContext() const
+{
+    std::string res;
+    for (auto & elt : context) {
+        res.append(encodeContext(elt.second, elt.first));
+        res.push_back(' ');
+    }
+    if (!res.empty())
+        res.pop_back(); // Remove the trailing space
+    return res;
+}
+
+}

src/libexpr/tree-cache.hh

@@ -0,0 +1,156 @@
+/**
+ * caching for a tree-like data structure (like Nix values)
+ *
+ * The cache is an sqlite db whose rows are the nodes of the tree, with a
+ * pointer to their parent (except for the root of course)
+ */
+
+#pragma once
+
+#include "sync.hh"
+#include "hash.hh"
+#include "symbol-table.hh"
+
+#include <functional>
+#include <variant>
+
+namespace nix::tree_cache {
+
+struct AttrDb;
+class Cursor;
+
+class Cache : public std::enable_shared_from_this<Cache>
+{
+private:
+    friend class Cursor;
+
+    /**
+     * The database holding the cache
+     */
+    std::shared_ptr<AttrDb> db;
+
+    SymbolTable & symbols;
+
+    /**
+     * Distinguished symbol indicating the root of the tree
+     */
+    const Symbol rootSymbol;
+
+public:
+
+    Cache(
+        const Hash & useCache,
+        SymbolTable & symbols
+    );
+
+    static std::shared_ptr<Cache> tryCreate(const Hash & useCache, SymbolTable & symbols);
+
+    Cursor * getRoot();
+
+    /**
+     * Flush the cache to disk
+     */
+    void commit();
+};
+
+enum AttrType {
+    Unknown = 0,
+    Attrs = 1,
+    String = 2,
+    Bool = 3,
+    Int = 4,
+    Double = 5,
+    Thunk = 6,
+    Missing = 7, // Missing fields of attribute sets
+    Failed = 8,
+};
+
+struct attributeSet_t {};
+struct unknown_t {};
+struct thunk_t {};
+struct failed_t { string error; };
+struct missing_t { Symbol attrName; };
+
+// Putting several different primitive types in an `std::variant` partially
+// breaks the `std::visit(overloaded{...` hackery because of the implicit cast
+// from one to another which breaks the exhaustiveness check.
+// So we wrap them in a trivial class just to force the disambiguation
+template<typename T>
+struct wrapped_basetype{ T value; };
+
+typedef uint64_t AttrId;
+
+typedef std::pair<AttrId, Symbol> AttrKey;
+typedef std::pair<std::string, std::vector<std::pair<Path, std::string>>> string_t;
+
+typedef std::variant<
+    attributeSet_t,
+    string_t,
+    unknown_t,
+    thunk_t,
+    missing_t,
+    failed_t,
+    wrapped_basetype<bool>,
+    wrapped_basetype<int64_t>,
+    wrapped_basetype<double>
+> AttrValue;
+
+struct RawValue {
+    AttrType type;
+    std::optional<std::string> value;
+    std::vector<std::pair<Path, std::string>> context;
+
+    std::string serializeContext() const;
+
+    static const RawValue fromVariant(const AttrValue&);
+    AttrValue toVariant() const;
+};
+
+/**
+ * View inside the cache.
+ *
+ * A `Cursor` represents a node in the cached tree (be it a leaf or not)
+ */
+class Cursor : public std::enable_shared_from_this<Cursor>
+{
+    /**
+     * The overall cache of which this cursor is a view
+     */
+    ref<Cache> root;
+
+    typedef std::optional<std::pair<Cursor&, Symbol>> Parent;
+
+    std::optional<AttrId> parentId;
+    Symbol label;
+
+    std::pair<AttrId, AttrValue> cachedValue;
+
+    /**
+     * Get the identifier for this node in the database
+     */
+    AttrKey getKey();
+
+public:
+
+    using Ref = Cursor*;
+
+    // Create a new cache entry
+    Cursor(ref<Cache> root, const Parent & parent, const AttrValue&);
+    // Build a cursor from an existing cache entry
+    Cursor(ref<Cache> root, const Parent & parent, const AttrId& id, const AttrValue&);
+
+    AttrValue getCachedValue();
+
+    void setValue(const AttrValue & v);
+
+    Ref addChild(const Symbol & attrPath, const AttrValue & v);
+
+    Ref findAlongAttrPath(const std::vector<Symbol> & attrPath);
+    Ref maybeGetAttr(const Symbol & attrPath);
+
+
+    std::vector<std::string> getChildren();
+    std::optional<std::vector<std::string>> getChildrenAtPath(const std::vector<Symbol> & attrPath);
+};
+
+}

src/libexpr/value-cache.hh

@@ -0,0 +1,51 @@
+#pragma once
+#include "tree-cache.hh"
+
+namespace nix {
+struct Value;
+class EvalState;
+class Bindings;
+
+class ValueCache {
+    tree_cache::Cursor::Ref rawCache;
+
+public:
+
+    ValueCache(tree_cache::Cursor::Ref rawCache) : rawCache(rawCache) {}
+
+    static ValueCache empty;
+
+    bool isEmpty () { return rawCache == nullptr; }
+
+    enum ReturnCode {
+        // The cache result was an attribute set, so we forward it later in the
+        // chain
+        Forward,
+        CacheMiss,
+        CacheHit,
+        UnCacheable,
+        NoCacheKey,
+    };
+
+    struct CacheResult {
+        ReturnCode returnCode;
+
+        // In case the query returns a `missing_t`, the symbol that's missing
+        std::optional<Symbol> lastQueriedSymbolIfMissing;
+    };
+    std::pair<CacheResult, ValueCache> getValue(EvalState & state, const std::vector<Symbol> & selector, Value & dest);
+
+    ValueCache addChild(const Symbol & attrName, Value & value);
+    ValueCache addFailedChild(const Symbol & attrName, const Error & error);
+    ValueCache addNumChild(SymbolTable & symbols, int idx, const Value & value);
+    void addAttrSetChilds(Bindings & children);
+    void addListChilds(SymbolTable & symbols, Value** elems, int listSize);
+
+    std::optional<std::vector<Symbol>> listChildren(SymbolTable&);
+    std::optional<std::vector<Symbol>> listChildrenAtPath(SymbolTable&, const std::vector<Symbol> & attrPath);
+
+    std::optional<tree_cache::AttrValue> getRawValue();
+
+    ValueCache() : rawCache(nullptr) {}
+};
+}

src/libexpr/value.hh

@@ -23,6 +23,7 @@ typedef enum {
     tApp,
     tLambda,
     tBlackhole,
+    tCachedThunk,
     tPrimOp,
     tPrimOpApp,
     tExternal,
@@ -56,6 +57,7 @@ struct Pos;
 class EvalState;
 class XMLWriter;
 class JSONPlaceholder;
+class ValueCache;
 
 
 typedef int64_t NixInt;
@@ -103,6 +105,10 @@ class ExternalValueBase
 
 std::ostream & operator << (std::ostream & str, const ExternalValueBase & v);
 
+struct Thunk {
+    Env * env;
+    Expr * expr;
+};
 
 struct Value
 {
@@ -122,6 +128,7 @@ public:
     inline bool isThunk() const { return internalType == tThunk; };
     inline bool isApp() const { return internalType == tApp; };
     inline bool isBlackhole() const { return internalType == tBlackhole; };
+    inline bool isCachedThunk() const { return internalType == tCachedThunk; };
 
     // type() == nFunction
     inline bool isLambda() const { return internalType == tLambda; };
@@ -165,10 +172,13 @@ public:
             Value * * elems;
         } bigList;
         Value * smallList[2];
+        Thunk thunk;
         struct {
-            Env * env;
-            Expr * expr;
-        } thunk;
+            Thunk * thunk;
+            // This is a pointer only to prevent a recursive import as
+            // `EvalCache` is already a pointer so would fit very nicely here.
+            ValueCache * cache;
+        } cachedThunk;
         struct {
             Value * left, * right;
         } app;
@@ -199,7 +209,7 @@ public:
             case tLambda: case tPrimOp: case tPrimOpApp: return nFunction;
             case tExternal: return nExternal;
             case tFloat: return nFloat;
-            case tThunk: case tApp: case tBlackhole: return nThunk;
+            case tThunk: case tApp: case tBlackhole: case tCachedThunk: return nThunk;
         }
         abort();
     }
@@ -272,6 +282,13 @@ public:
         thunk.expr = ex;
     }
 
+    inline void mkCachedThunk(Thunk * t, ValueCache * cache)
+    {
+        internalType = tCachedThunk;
+        cachedThunk.thunk = t;
+        cachedThunk.cache = cache;
+    }
+
     inline void mkApp(Value * l, Value * r)
     {
         internalType = tApp;
@@ -349,6 +366,9 @@ public:
     bool isTrivial() const;
 
     std::vector<std::pair<Path, std::string>> getContext();
+
+    ValueCache & getEvalCache();
+    void setEvalCache(ValueCache &);
 };
 
 

src/libfetchers/fetchers.cc

@@ -200,17 +200,12 @@ void Input::markChangedFile(
     return scheme->markChangedFile(*this, file, commitMsg);
 }
 
-std::string Input::getName() const
-{
-    return maybeGetStrAttr(attrs, "name").value_or("source");
-}
-
 StorePath Input::computeStorePath(Store & store) const
 {
     auto narHash = getNarHash();
     if (!narHash)
         throw Error("cannot compute store path for mutable input '%s'", to_string());
-    return store.makeFixedOutputPath(FileIngestionMethod::Recursive, *narHash, getName());
+    return store.makeFixedOutputPath(FileIngestionMethod::Recursive, *narHash, "source");
 }
 
 std::string Input::getType() const

src/libfetchers/fetchers.hh

@@ -81,8 +81,6 @@ public:
         std::string_view file,
         std::optional<std::string> commitMsg) const;
 
-    std::string getName() const;
-
     StorePath computeStorePath(Store & store) const;
 
     // Convenience functions for common attributes.

src/libfetchers/git.cc

@@ -4,7 +4,6 @@
 #include "tarfile.hh"
 #include "store-api.hh"
 #include "url-parts.hh"
-#include "pathlocks.hh"
 
 #include <sys/time.h>
 #include <sys/wait.h>
@@ -61,7 +60,7 @@ struct GitInputScheme : InputScheme
         if (maybeGetStrAttr(attrs, "type") != "git") return {};
 
         for (auto & [name, value] : attrs)
-            if (name != "type" && name != "url" && name != "ref" && name != "rev" && name != "shallow" && name != "submodules" && name != "lastModified" && name != "revCount" && name != "narHash" && name != "allRefs" && name != "name")
+            if (name != "type" && name != "url" && name != "ref" && name != "rev" && name != "shallow" && name != "submodules" && name != "lastModified" && name != "revCount" && name != "narHash" && name != "allRefs")
                 throw Error("unsupported Git input attribute '%s'", name);
 
         parseURL(getStrAttr(attrs, "url"));
@@ -168,9 +167,9 @@ struct GitInputScheme : InputScheme
 
     std::pair<Tree, Input> fetch(ref<Store> store, const Input & _input) override
     {
-        Input input(_input);
+        auto name = "source";
 
-        std::string name = input.getName();
+        Input input(_input);
 
         bool shallow = maybeGetBoolAttr(input.attrs, "shallow").value_or(false);
         bool submodules = maybeGetBoolAttr(input.attrs, "submodules").value_or(false);
@@ -271,7 +270,7 @@ struct GitInputScheme : InputScheme
                     return files.count(file);
                 };
 
-                auto storePath = store->addToStore(input.getName(), actualUrl, FileIngestionMethod::Recursive, htSHA256, filter);
+                auto storePath = store->addToStore("source", actualUrl, FileIngestionMethod::Recursive, htSHA256, filter);
 
                 // FIXME: maybe we should use the timestamp of the last
                 // modified dirty file?
@@ -318,17 +317,11 @@ struct GitInputScheme : InputScheme
             Path cacheDir = getCacheDir() + "/nix/gitv3/" + hashString(htSHA256, actualUrl).to_string(Base32, false);
             repoDir = cacheDir;
 
-            Path cacheDirLock = cacheDir + ".lock";
-            createDirs(dirOf(cacheDir));
-            AutoCloseFD lock = openLockFile(cacheDirLock, true);
-            lockFile(lock.get(), ltWrite, true);
-
             if (!pathExists(cacheDir)) {
+                createDirs(dirOf(cacheDir));
                 runProgram("git", true, { "init", "--bare", repoDir });
             }
 
-            deleteLockFile(cacheDirLock, lock.get());
-
             Path localRefFile =
                 input.getRef()->compare(0, 5, "refs/") == 0
                 ? cacheDir + "/" + *input.getRef()

src/libfetchers/github.cc

@@ -207,7 +207,7 @@ struct GitArchiveInputScheme : InputScheme
 
         auto url = getDownloadUrl(input);
 
-        auto [tree, lastModified] = downloadTarball(store, url.url, input.getName(), true, url.headers);
+        auto [tree, lastModified] = downloadTarball(store, url.url, "source", true, url.headers);
 
         input.attrs.insert_or_assign("lastModified", uint64_t(lastModified));
 

src/libfetchers/local.mk

@@ -8,6 +8,4 @@ libfetchers_SOURCES := $(wildcard $(d)/*.cc)
 
 libfetchers_CXXFLAGS += -I src/libutil -I src/libstore
 
-libfetchers_LDFLAGS = -pthread
-
 libfetchers_LIBS = libutil libstore

src/libfetchers/mercurial.cc

@@ -74,7 +74,7 @@ struct MercurialInputScheme : InputScheme
         if (maybeGetStrAttr(attrs, "type") != "hg") return {};
 
         for (auto & [name, value] : attrs)
-            if (name != "type" && name != "url" && name != "ref" && name != "rev" && name != "revCount" && name != "narHash" && name != "name")
+            if (name != "type" && name != "url" && name != "ref" && name != "rev" && name != "revCount" && name != "narHash")
                 throw Error("unsupported Mercurial input attribute '%s'", name);
 
         parseURL(getStrAttr(attrs, "url"));
@@ -147,9 +147,9 @@ struct MercurialInputScheme : InputScheme
 
     std::pair<Tree, Input> fetch(ref<Store> store, const Input & _input) override
     {
-        Input input(_input);
+        auto name = "source";
 
-        auto name = input.getName();
+        Input input(_input);
 
         auto [isLocal, actualUrl_] = getActualUrl(input);
         auto actualUrl = actualUrl_; // work around clang bug
@@ -193,7 +193,7 @@ struct MercurialInputScheme : InputScheme
                     return files.count(file);
                 };
 
-                auto storePath = store->addToStore(input.getName(), actualUrl, FileIngestionMethod::Recursive, htSHA256, filter);
+                auto storePath = store->addToStore("source", actualUrl, FileIngestionMethod::Recursive, htSHA256, filter);
 
                 return {
                     Tree(store->toRealPath(storePath), std::move(storePath)),

src/libfetchers/registry.cc

@@ -124,13 +124,6 @@ std::shared_ptr<Registry> getUserRegistry()
     return userRegistry;
 }
 
-std::shared_ptr<Registry> getCustomRegistry(const Path & p)
-{
-    static auto customRegistry =
-        Registry::read(p, Registry::Custom);
-    return customRegistry;
-}
-
 static std::shared_ptr<Registry> flagRegistry =
     std::make_shared<Registry>(Registry::Flag);
 

src/libfetchers/registry.hh

@@ -14,7 +14,6 @@ struct Registry
         User = 1,
         System = 2,
         Global = 3,
-        Custom = 4,
     };
 
     RegistryType type;
@@ -49,8 +48,6 @@ typedef std::vector<std::shared_ptr<Registry>> Registries;
 
 std::shared_ptr<Registry> getUserRegistry();
 
-std::shared_ptr<Registry> getCustomRegistry(const Path & p);
-
 Path getUserRegistryPath();
 
 Registries getRegistries(ref<Store> store);

src/libfetchers/tarball.cc

@@ -196,7 +196,7 @@ struct TarballInputScheme : InputScheme
         if (maybeGetStrAttr(attrs, "type") != "tarball") return {};
 
         for (auto & [name, value] : attrs)
-            if (name != "type" && name != "url" && /* name != "hash" && */ name != "narHash" && name != "name")
+            if (name != "type" && name != "url" && /* name != "hash" && */ name != "narHash")
                 throw Error("unsupported tarball input attribute '%s'", name);
 
         Input input;
@@ -226,7 +226,7 @@ struct TarballInputScheme : InputScheme
 
     std::pair<Tree, Input> fetch(ref<Store> store, const Input & input) override
     {
-        auto tree = downloadTarball(store, getStrAttr(input.attrs, "url"), input.getName(), false).first;
+        auto tree = downloadTarball(store, getStrAttr(input.attrs, "url"), "source", false).first;
         return {std::move(tree), input};
     }
 };

src/libmain/local.mk

@@ -14,4 +14,4 @@ libmain_LIBS = libstore libutil
 
 libmain_ALLOW_UNDEFINED = 1
 
-$(eval $(call install-file-in, $(d)/nix-main.pc, $(libdir)/pkgconfig, 0644))
+$(eval $(call install-file-in, $(d)/nix-main.pc, $(prefix)/lib/pkgconfig, 0644))

src/libmain/progress-bar.cc

@@ -484,7 +484,7 @@ Logger * makeProgressBar(bool printBuildLogs)
 {
     return new ProgressBar(
         printBuildLogs,
-        shouldANSI()
+        isatty(STDERR_FILENO) && getEnv("TERM").value_or("dumb") != "dumb"
     );
 }
 

src/libmain/shared.cc

@@ -238,7 +238,7 @@ LegacyArgs::LegacyArgs(const std::string & programName,
     addFlag({
         .longName = "no-gc-warning",
         .description = "Disable warnings about not using `--add-root`.",
-        .handler = {&gcWarning, false},
+        .handler = {&gcWarning, true},
     });
 
     addFlag({

src/libstore/binary-cache-store.cc

@@ -130,6 +130,17 @@ AutoCloseFD openFile(const Path & path)
     return fd;
 }
 
+struct FileSource : FdSource
+{
+    AutoCloseFD fd2;
+
+    FileSource(const Path & path)
+        : fd2(openFile(path))
+    {
+        fd = fd2.get();
+    }
+};
+
 ref<const ValidPathInfo> BinaryCacheStore::addToStoreCommon(
     Source & narSource, RepairFlag repair, CheckSigsFlag checkSigs,
     std::function<ValidPathInfo(HashResult)> mkInfo)

src/libstore/build/derivation-goal.cc

@@ -143,6 +143,7 @@ void DerivationGoal::work()
     (this->*state)();
 }
 
+
 void DerivationGoal::addWantedOutputs(const StringSet & outputs)
 {
     /* If we already want all outputs, there is nothing to do. */
@@ -165,7 +166,7 @@ void DerivationGoal::getDerivation()
     /* The first thing to do is to make sure that the derivation
        exists.  If it doesn't, it may be created through a
        substitute. */
-    if (buildMode == bmNormal && worker.evalStore.isValidPath(drvPath)) {
+    if (buildMode == bmNormal && worker.store.isValidPath(drvPath)) {
         loadDerivation();
         return;
     }
@@ -188,12 +189,12 @@ void DerivationGoal::loadDerivation()
     /* `drvPath' should already be a root, but let's be on the safe
        side: if the user forgot to make it a root, we wouldn't want
        things being garbage collected while we're busy. */
-    worker.evalStore.addTempRoot(drvPath);
+    worker.store.addTempRoot(drvPath);
 
-    assert(worker.evalStore.isValidPath(drvPath));
+    assert(worker.store.isValidPath(drvPath));
 
     /* Get the derivation. */
-    drv = std::make_unique<Derivation>(worker.evalStore.derivationFromPath(drvPath));
+    drv = std::make_unique<Derivation>(worker.store.derivationFromPath(drvPath));
 
     haveDerivation();
 }
@@ -212,8 +213,8 @@ void DerivationGoal::haveDerivation()
         if (i.second.second)
             worker.store.addTempRoot(*i.second.second);
 
-    auto outputHashes = staticOutputHashes(worker.evalStore, *drv);
-    for (auto & [outputName, outputHash] : outputHashes)
+    auto outputHashes = staticOutputHashes(worker.store, *drv);
+    for (auto &[outputName, outputHash] : outputHashes)
       initialOutputs.insert({
             outputName,
             InitialOutput{
@@ -337,15 +338,6 @@ void DerivationGoal::gaveUpOnSubstitution()
         for (auto & i : dynamic_cast<Derivation *>(drv.get())->inputDrvs)
             addWaitee(worker.makeDerivationGoal(i.first, i.second, buildMode == bmRepair ? bmRepair : bmNormal));
 
-    /* Copy the input sources from the eval store to the build
-       store. */
-    if (&worker.evalStore != &worker.store) {
-        RealisedPath::Set inputSrcs;
-        for (auto & i : drv->inputSrcs)
-            inputSrcs.insert(i);
-        copyClosure(worker.evalStore, worker.store, inputSrcs);
-    }
-
     for (auto & i : drv->inputSrcs) {
         if (worker.store.isValidPath(i)) continue;
         if (!settings.useSubstitutes)
@@ -487,8 +479,8 @@ void DerivationGoal::inputsRealised()
             /* Add the relevant output closures of the input derivation
                `i' as input paths.  Only add the closures of output paths
                that are specified as inputs. */
-            assert(worker.evalStore.isValidPath(drvPath));
-            auto outputs = worker.evalStore.queryPartialDerivationOutputMap(depDrvPath);
+            assert(worker.store.isValidPath(drvPath));
+            auto outputs = worker.store.queryPartialDerivationOutputMap(depDrvPath);
             for (auto & j : wantedDepOutputs) {
                 if (outputs.count(j) > 0) {
                     auto optRealizedInput = outputs.at(j);
@@ -553,7 +545,7 @@ void DerivationGoal::tryToBuild()
     PathSet lockFiles;
     /* FIXME: Should lock something like the drv itself so we don't build same
        CA drv concurrently */
-    if (dynamic_cast<LocalStore *>(&worker.store)) {
+    if (dynamic_cast<LocalStore *>(&worker.store))
         /* If we aren't a local store, we might need to use the local store as
            a build remote, but that would cause a deadlock. */
         /* FIXME: Make it so we can use ourselves as a build remote even if we
@@ -561,15 +553,9 @@ void DerivationGoal::tryToBuild()
         /* FIXME: find some way to lock for scheduling for the other stores so
            a forking daemon with --store still won't farm out redundant builds.
            */
-        for (auto & i : drv->outputsAndOptPaths(worker.store)) {
+        for (auto & i : drv->outputsAndOptPaths(worker.store))
             if (i.second.second)
                 lockFiles.insert(worker.store.Store::toRealPath(*i.second.second));
-            else
-                lockFiles.insert(
-                    worker.store.Store::toRealPath(drvPath) + "!" + i.first
-                );
-        }
-    }
 
     if (!outputLocks.lockPaths(lockFiles, "", false)) {
         if (!actLock)
@@ -753,64 +739,6 @@ void DerivationGoal::cleanupPostOutputsRegisteredModeNonCheck()
 {
 }
 
-void runPostBuildHook(
-    Store & store,
-    Logger & logger,
-    const StorePath & drvPath,
-    StorePathSet outputPaths
-)
-{
-    auto hook = settings.postBuildHook;
-    if (hook == "")
-        return;
-
-    Activity act(logger, lvlInfo, actPostBuildHook,
-            fmt("running post-build-hook '%s'", settings.postBuildHook),
-            Logger::Fields{store.printStorePath(drvPath)});
-    PushActivity pact(act.id);
-    std::map<std::string, std::string> hookEnvironment = getEnv();
-
-    hookEnvironment.emplace("DRV_PATH", store.printStorePath(drvPath));
-    hookEnvironment.emplace("OUT_PATHS", chomp(concatStringsSep(" ", store.printStorePathSet(outputPaths))));
-    hookEnvironment.emplace("NIX_CONFIG", globalConfig.toKeyValue());
-
-    RunOptions opts(settings.postBuildHook, {});
-    opts.environment = hookEnvironment;
-
-    struct LogSink : Sink {
-        Activity & act;
-        std::string currentLine;
-
-        LogSink(Activity & act) : act(act) { }
-
-        void operator() (std::string_view data) override {
-            for (auto c : data) {
-                if (c == '\n') {
-                    flushLine();
-                } else {
-                    currentLine += c;
-                }
-            }
-        }
-
-        void flushLine() {
-            act.result(resPostBuildLogLine, currentLine);
-            currentLine.clear();
-        }
-
-        ~LogSink() {
-            if (currentLine != "") {
-                currentLine += '\n';
-                flushLine();
-            }
-        }
-    };
-    LogSink sink(act);
-
-    opts.standardOut = &sink;
-    opts.mergeStderrToStdout = true;
-    runProgram2(opts);
-}
 
 void DerivationGoal::buildDone()
 {
@@ -876,15 +804,57 @@ void DerivationGoal::buildDone()
            being valid. */
         registerOutputs();
 
-        StorePathSet outputPaths;
-        for (auto & [_, path] : finalOutputs)
-            outputPaths.insert(path);
-        runPostBuildHook(
-            worker.store,
-            *logger,
-            drvPath,
-            outputPaths
-        );
+        if (settings.postBuildHook != "") {
+            Activity act(*logger, lvlInfo, actPostBuildHook,
+                fmt("running post-build-hook '%s'", settings.postBuildHook),
+                Logger::Fields{worker.store.printStorePath(drvPath)});
+            PushActivity pact(act.id);
+            StorePathSet outputPaths;
+            for (auto i : drv->outputs) {
+                outputPaths.insert(finalOutputs.at(i.first));
+            }
+            std::map<std::string, std::string> hookEnvironment = getEnv();
+
+            hookEnvironment.emplace("DRV_PATH", worker.store.printStorePath(drvPath));
+            hookEnvironment.emplace("OUT_PATHS", chomp(concatStringsSep(" ", worker.store.printStorePathSet(outputPaths))));
+
+            RunOptions opts(settings.postBuildHook, {});
+            opts.environment = hookEnvironment;
+
+            struct LogSink : Sink {
+                Activity & act;
+                std::string currentLine;
+
+                LogSink(Activity & act) : act(act) { }
+
+                void operator() (std::string_view data) override {
+                    for (auto c : data) {
+                        if (c == '\n') {
+                            flushLine();
+                        } else {
+                            currentLine += c;
+                        }
+                    }
+                }
+
+                void flushLine() {
+                    act.result(resPostBuildLogLine, currentLine);
+                    currentLine.clear();
+                }
+
+                ~LogSink() {
+                    if (currentLine != "") {
+                        currentLine += '\n';
+                        flushLine();
+                    }
+                }
+            };
+            LogSink sink(act);
+
+            opts.standardOut = &sink;
+            opts.mergeStderrToStdout = true;
+            runProgram2(opts);
+        }
 
         if (buildMode == bmCheck) {
             cleanupPostOutputsRegisteredModeCheck();
@@ -940,8 +910,6 @@ void DerivationGoal::resolvedFinished() {
 
     auto resolvedHashes = staticOutputHashes(worker.store, *resolvedDrv);
 
-    StorePathSet outputPaths;
-
     // `wantedOutputs` might be empty, which means “all the outputs”
     auto realWantedOutputs = wantedOutputs;
     if (realWantedOutputs.empty())
@@ -959,10 +927,8 @@ void DerivationGoal::resolvedFinished() {
             auto newRealisation = *realisation;
             newRealisation.id = DrvOutput{initialOutputs.at(wantedOutput).outputHash, wantedOutput};
             newRealisation.signatures.clear();
-            newRealisation.dependentRealisations = drvOutputReferences(worker.store, *drv, realisation->outPath);
             signRealisation(newRealisation);
             worker.store.registerDrvOutput(newRealisation);
-            outputPaths.insert(realisation->outPath);
         } else {
             // If we don't have a realisation, then it must mean that something
             // failed when building the resolved drv
@@ -970,13 +936,6 @@ void DerivationGoal::resolvedFinished() {
         }
     }
 
-    runPostBuildHook(
-        worker.store,
-        *logger,
-        drvPath,
-        outputPaths
-    );
-
     // This is potentially a bit fishy in terms of error reporting. Not sure
     // how to do it in a cleaner way
     amDone(nrFailed == 0 ? ecSuccess : ecFailed, ex);
@@ -1089,6 +1048,42 @@ HookReply DerivationGoal::tryBuildHook()
 }
 
 
+StorePathSet DerivationGoal::exportReferences(const StorePathSet & storePaths)
+{
+    StorePathSet paths;
+
+    for (auto & storePath : storePaths) {
+        if (!inputPaths.count(storePath))
+            throw BuildError("cannot export references of path '%s' because it is not in the input closure of the derivation", worker.store.printStorePath(storePath));
+
+        worker.store.computeFSClosure({storePath}, paths);
+    }
+
+    /* If there are derivations in the graph, then include their
+       outputs as well.  This is useful if you want to do things
+       like passing all build-time dependencies of some path to a
+       derivation that builds a NixOS DVD image. */
+    auto paths2 = paths;
+
+    for (auto & j : paths2) {
+        if (j.isDerivation()) {
+            Derivation drv = worker.store.derivationFromPath(j);
+            for (auto & k : drv.outputsAndOptPaths(worker.store)) {
+                if (!k.second.second)
+                    /* FIXME: I am confused why we are calling
+                       `computeFSClosure` on the output path, rather than
+                       derivation itself. That doesn't seem right to me, so I
+                       won't try to implemented this for CA derivations. */
+                    throw UnimplementedError("exportReferences on CA derivations is not yet implemented");
+                worker.store.computeFSClosure(*k.second.second, paths);
+            }
+        }
+    }
+
+    return paths;
+}
+
+
 void DerivationGoal::registerOutputs()
 {
     /* When using a build hook, the build hook can register the output

src/libstore/build/drv-output-substitution-goal.cc

@@ -17,13 +17,6 @@ DrvOutputSubstitutionGoal::DrvOutputSubstitutionGoal(const DrvOutput& id, Worker
 void DrvOutputSubstitutionGoal::init()
 {
     trace("init");
-
-    /* If the derivation already exists, we’re done */
-    if (worker.store.queryRealisation(id)) {
-        amDone(ecSuccess);
-        return;
-    }
-
     subs = settings.useSubstitutes ? getDefaultSubstituters() : std::list<ref<Store>>();
     tryNext();
 }
@@ -60,26 +53,6 @@ void DrvOutputSubstitutionGoal::tryNext()
         return;
     }
 
-    for (const auto & [depId, depPath] : outputInfo->dependentRealisations) {
-        if (depId != id) {
-            if (auto localOutputInfo = worker.store.queryRealisation(depId);
-                localOutputInfo && localOutputInfo->outPath != depPath) {
-                warn(
-                    "substituter '%s' has an incompatible realisation for '%s', ignoring.\n"
-                    "Local:  %s\n"
-                    "Remote: %s",
-                    sub->getUri(),
-                    depId.to_string(),
-                    worker.store.printStorePath(localOutputInfo->outPath),
-                    worker.store.printStorePath(depPath)
-                );
-                tryNext();
-                return;
-            }
-            addWaitee(worker.makeDrvOutputSubstitutionGoal(depId));
-        }
-    }
-
     addWaitee(worker.makePathSubstitutionGoal(outputInfo->outPath));
 
     if (waitees.empty()) outPathValid();

src/libstore/build/entry-points.cc

@@ -6,9 +6,9 @@
 
 namespace nix {
 
-void Store::buildPaths(const std::vector<DerivedPath> & reqs, BuildMode buildMode, std::shared_ptr<Store> evalStore)
+void Store::buildPaths(const std::vector<DerivedPath> & reqs, BuildMode buildMode)
 {
-    Worker worker(*this, evalStore ? *evalStore : *this);
+    Worker worker(*this);
 
     Goals goals;
     for (auto & br : reqs) {
@@ -51,7 +51,7 @@ void Store::buildPaths(const std::vector<DerivedPath> & reqs, BuildMode buildMod
 BuildResult Store::buildDerivation(const StorePath & drvPath, const BasicDerivation & drv,
     BuildMode buildMode)
 {
-    Worker worker(*this, *this);
+    Worker worker(*this);
     auto goal = worker.makeBasicDerivationGoal(drvPath, drv, {}, buildMode);
 
     BuildResult result;
@@ -93,7 +93,7 @@ void Store::ensurePath(const StorePath & path)
     /* If the path is already valid, we're done. */
     if (isValidPath(path)) return;
 
-    Worker worker(*this, *this);
+    Worker worker(*this);
     GoalPtr goal = worker.makePathSubstitutionGoal(path);
     Goals goals = {goal};
 
@@ -111,7 +111,7 @@ void Store::ensurePath(const StorePath & path)
 
 void LocalStore::repairPath(const StorePath & path)
 {
-    Worker worker(*this, *this);
+    Worker worker(*this);
     GoalPtr goal = worker.makePathSubstitutionGoal(path, Repair);
     Goals goals = {goal};
 

src/libstore/build/goal.cc

@@ -13,9 +13,11 @@ bool CompareGoalPtrs::operator() (const GoalPtr & a, const GoalPtr & b) const {
 
 void addToWeakGoals(WeakGoals & goals, GoalPtr p)
 {
-    if (goals.find(p) != goals.end())
-        return;
-    goals.insert(p);
+    // FIXME: necessary?
+    // FIXME: O(n)
+    for (auto & i : goals)
+        if (i.lock() == p) return;
+    goals.push_back(p);
 }
 
 
@@ -44,7 +46,10 @@ void Goal::waiteeDone(GoalPtr waitee, ExitCode result)
         /* If we failed and keepGoing is not set, we remove all
            remaining waitees. */
         for (auto & goal : waitees) {
-            goal->waiters.extract(shared_from_this());
+            WeakGoals waiters2;
+            for (auto & j : goal->waiters)
+                if (j.lock() != shared_from_this()) waiters2.push_back(j);
+            goal->waiters = waiters2;
         }
         waitees.clear();
 

src/libstore/build/goal.hh

@@ -19,7 +19,7 @@ struct CompareGoalPtrs {
 
 /* Set of goals. */
 typedef set<GoalPtr, CompareGoalPtrs> Goals;
-typedef set<WeakGoalPtr, std::owner_less<WeakGoalPtr>> WeakGoals;
+typedef list<WeakGoalPtr> WeakGoals;
 
 /* A map of paths to goals (and the other way around). */
 typedef std::map<StorePath, WeakGoalPtr> WeakGoalMap;

src/libstore/build/local-derivation-goal.cc

@@ -292,7 +292,7 @@ bool LocalDerivationGoal::cleanupDecideWhetherDiskFull()
         auto & localStore = getLocalStore();
         uint64_t required = 8ULL * 1024 * 1024; // FIXME: make configurable
         struct statvfs st;
-        if (statvfs(localStore.realStoreDir.get().c_str(), &st) == 0 &&
+        if (statvfs(localStore.realStoreDir.c_str(), &st) == 0 &&
             (uint64_t) st.f_bavail * st.f_bsize < required)
             diskFull = true;
         if (statvfs(tmpDir.c_str(), &st) == 0 &&
@@ -417,7 +417,7 @@ void LocalDerivationGoal::startBuilder()
     }
 
     auto & localStore = getLocalStore();
-    if (localStore.storeDir != localStore.realStoreDir.get()) {
+    if (localStore.storeDir != localStore.realStoreDir) {
         #if __linux__
             useChroot = true;
         #else
@@ -518,7 +518,7 @@ void LocalDerivationGoal::startBuilder()
             /* Write closure info to <fileName>. */
             writeFile(tmpDir + "/" + fileName,
                 worker.store.makeValidityRegistration(
-                    worker.store.exportReferences({storePath}, inputPaths), false, false));
+                    exportReferences({storePath}), false, false));
         }
     }
 
@@ -1084,28 +1084,113 @@ void LocalDerivationGoal::initEnv()
 }
 
 
+static std::regex shVarName("[A-Za-z_][A-Za-z0-9_]*");
+
+
 void LocalDerivationGoal::writeStructuredAttrs()
 {
-    if (auto structAttrsJson = parsedDrv->prepareStructuredAttrs(worker.store, inputPaths)) {
-        auto json = structAttrsJson.value();
-        nlohmann::json rewritten;
-        for (auto & [i, v] : json["outputs"].get<nlohmann::json::object_t>()) {
-            /* The placeholder must have a rewrite, so we use it to cover both the
-               cases where we know or don't know the output path ahead of time. */
-            rewritten[i] = rewriteStrings(v, inputRewrites);
+    auto structuredAttrs = parsedDrv->getStructuredAttrs();
+    if (!structuredAttrs) return;
+
+    auto json = *structuredAttrs;
+
+    /* Add an "outputs" object containing the output paths. */
+    nlohmann::json outputs;
+    for (auto & i : drv->outputs) {
+        /* The placeholder must have a rewrite, so we use it to cover both the
+           cases where we know or don't know the output path ahead of time. */
+        outputs[i.first] = rewriteStrings(hashPlaceholder(i.first), inputRewrites);
+    }
+    json["outputs"] = outputs;
+
+    /* Handle exportReferencesGraph. */
+    auto e = json.find("exportReferencesGraph");
+    if (e != json.end() && e->is_object()) {
+        for (auto i = e->begin(); i != e->end(); ++i) {
+            std::ostringstream str;
+            {
+                JSONPlaceholder jsonRoot(str, true);
+                StorePathSet storePaths;
+                for (auto & p : *i)
+                    storePaths.insert(worker.store.parseStorePath(p.get<std::string>()));
+                worker.store.pathInfoToJSON(jsonRoot,
+                    exportReferences(storePaths), false, true);
+            }
+            json[i.key()] = nlohmann::json::parse(str.str()); // urgh
+        }
+    }
+
+    writeFile(tmpDir + "/.attrs.json", rewriteStrings(json.dump(), inputRewrites));
+    chownToBuilder(tmpDir + "/.attrs.json");
+
+    /* As a convenience to bash scripts, write a shell file that
+       maps all attributes that are representable in bash -
+       namely, strings, integers, nulls, Booleans, and arrays and
+       objects consisting entirely of those values. (So nested
+       arrays or objects are not supported.) */
+
+    auto handleSimpleType = [](const nlohmann::json & value) -> std::optional<std::string> {
+        if (value.is_string())
+            return shellEscape(value);
+
+        if (value.is_number()) {
+            auto f = value.get<float>();
+            if (std::ceil(f) == f)
+                return std::to_string(value.get<int>());
         }
 
-        json["outputs"] = rewritten;
+        if (value.is_null())
+            return std::string("''");
 
-        auto jsonSh = writeStructuredAttrsShell(json);
+        if (value.is_boolean())
+            return value.get<bool>() ? std::string("1") : std::string("");
 
-        writeFile(tmpDir + "/.attrs.sh", rewriteStrings(jsonSh, inputRewrites));
-        chownToBuilder(tmpDir + "/.attrs.sh");
-        env["NIX_ATTRS_SH_FILE"] = tmpDir + "/.attrs.sh";
-        writeFile(tmpDir + "/.attrs.json", rewriteStrings(json.dump(), inputRewrites));
-        chownToBuilder(tmpDir + "/.attrs.json");
-        env["NIX_ATTRS_JSON_FILE"] = tmpDir + "/.attrs.json";
+        return {};
+    };
+
+    std::string jsonSh;
+
+    for (auto i = json.begin(); i != json.end(); ++i) {
+
+        if (!std::regex_match(i.key(), shVarName)) continue;
+
+        auto & value = i.value();
+
+        auto s = handleSimpleType(value);
+        if (s)
+            jsonSh += fmt("declare %s=%s\n", i.key(), *s);
+
+        else if (value.is_array()) {
+            std::string s2;
+            bool good = true;
+
+            for (auto i = value.begin(); i != value.end(); ++i) {
+                auto s3 = handleSimpleType(i.value());
+                if (!s3) { good = false; break; }
+                s2 += *s3; s2 += ' ';
+            }
+
+            if (good)
+                jsonSh += fmt("declare -a %s=(%s)\n", i.key(), s2);
+        }
+
+        else if (value.is_object()) {
+            std::string s2;
+            bool good = true;
+
+            for (auto i = value.begin(); i != value.end(); ++i) {
+                auto s3 = handleSimpleType(i.value());
+                if (!s3) { good = false; break; }
+                s2 += fmt("[%s]=%s ", shellEscape(i.key()), *s3);
+            }
+
+            if (good)
+                jsonSh += fmt("declare -A %s=(%s)\n", i.key(), s2);
+        }
     }
+
+    writeFile(tmpDir + "/.attrs.sh", rewriteStrings(jsonSh, inputRewrites));
+    chownToBuilder(tmpDir + "/.attrs.sh");
 }
 
 
@@ -1248,20 +1333,13 @@ struct RestrictedStore : public virtual RestrictedStoreConfig, public virtual Lo
     std::optional<const Realisation> queryRealisation(const DrvOutput & id) override
     // XXX: This should probably be allowed if the realisation corresponds to
     // an allowed derivation
-    {
-        if (!goal.isAllowed(id))
-            throw InvalidPath("cannot query an unknown output id '%s' in recursive Nix", id.to_string());
-        return next->queryRealisation(id);
-    }
+    { throw Error("queryRealisation"); }
 
-    void buildPaths(const std::vector<DerivedPath> & paths, BuildMode buildMode, std::shared_ptr<Store> evalStore) override
+    void buildPaths(const std::vector<DerivedPath> & paths, BuildMode buildMode) override
     {
-        assert(!evalStore);
-
         if (buildMode != bmNormal) throw Error("unsupported build mode");
 
         StorePathSet newPaths;
-        std::set<Realisation> newRealisations;
 
         for (auto & req : paths) {
             if (!goal.isAllowed(req))
@@ -1274,28 +1352,16 @@ struct RestrictedStore : public virtual RestrictedStoreConfig, public virtual Lo
             auto p =  std::get_if<DerivedPath::Built>(&path);
             if (!p) continue;
             auto & bfd = *p;
-            auto drv = readDerivation(bfd.drvPath);
-            auto drvHashes = staticOutputHashes(*this, drv);
             auto outputs = next->queryDerivationOutputMap(bfd.drvPath);
             for (auto & [outputName, outputPath] : outputs)
-                if (wantOutput(outputName, bfd.outputs)) {
+                if (wantOutput(outputName, bfd.outputs))
                     newPaths.insert(outputPath);
-                    if (settings.isExperimentalFeatureEnabled("ca-derivations")) {
-                        auto thisRealisation = next->queryRealisation(
-                            DrvOutput{drvHashes.at(outputName), outputName}
-                        );
-                        assert(thisRealisation);
-                        newRealisations.insert(*thisRealisation);
-                    }
-                }
         }
 
         StorePathSet closure;
         next->computeFSClosure(newPaths, closure);
         for (auto & path : closure)
             goal.addDependency(path);
-        for (auto & real : Realisation::closure(*next, newRealisations))
-            goal.addedDrvOutputs.insert(real.id);
     }
 
     BuildResult buildDerivation(const StorePath & drvPath, const BasicDerivation & drv,
@@ -1671,7 +1737,7 @@ void LocalDerivationGoal::runChild()
                 /* N.B. it is realistic that these paths might not exist. It
                    happens when testing Nix building fixed-output derivations
                    within a pure derivation. */
-                for (auto & path : { "/etc/resolv.conf", "/etc/services", "/etc/hosts" })
+                for (auto & path : { "/etc/resolv.conf", "/etc/services", "/etc/hosts", "/var/run/nscd/socket" })
                     if (pathExists(path))
                         ss.push_back(path);
             }
@@ -2398,7 +2464,6 @@ void LocalDerivationGoal::registerOutputs()
            floating CA derivations and hash-mismatching fixed-output
            derivations. */
         PathLocks dynamicOutputLock;
-        dynamicOutputLock.setDeletion(true);
         auto optFixedPath = output.path(worker.store, drv->name, outputName);
         if (!optFixedPath ||
             worker.store.printStorePath(*optFixedPath) != finalDestPath)
@@ -2422,7 +2487,6 @@ void LocalDerivationGoal::registerOutputs()
                 assert(newInfo.ca);
             } else {
                 auto destPath = worker.store.toRealPath(finalDestPath);
-                deletePath(destPath);
                 movePath(actualPath, destPath);
                 actualPath = destPath;
             }

src/libstore/build/local-derivation-goal.hh

@@ -108,9 +108,6 @@ struct LocalDerivationGoal : public DerivationGoal
     /* Paths that were added via recursive Nix calls. */
     StorePathSet addedPaths;
 
-    /* Realisations that were added via recursive Nix calls. */
-    std::set<DrvOutput> addedDrvOutputs;
-
     /* Recursive Nix calls are only allowed to build or realize paths
        in the original input closure or added via a recursive Nix call
        (so e.g. you can't do 'nix-store -r /nix/store/<bla>' where
@@ -119,11 +116,6 @@ struct LocalDerivationGoal : public DerivationGoal
     {
         return inputPaths.count(path) || addedPaths.count(path);
     }
-    bool isAllowed(const DrvOutput & id)
-    {
-        return addedDrvOutputs.count(id);
-    }
-
     bool isAllowed(const DerivedPath & req);
 
     friend struct RestrictedStore;

src/libstore/build/substitution-goal.cc

@@ -204,7 +204,7 @@ void PathSubstitutionGoal::tryToRun()
             Activity act(*logger, actSubstitute, Logger::Fields{worker.store.printStorePath(storePath), sub->getUri()});
             PushActivity pact(act.id);
 
-            copyStorePath(*sub, worker.store,
+            copyStorePath(ref<Store>(sub), ref<Store>(worker.store.shared_from_this()),
                 subPath ? *subPath : storePath, repair, sub->isTrusted ? NoCheckSigs : CheckSigs);
 
             promise.set_value();

src/libstore/build/worker.cc

@@ -9,12 +9,11 @@
 
 namespace nix {
 
-Worker::Worker(Store & store, Store & evalStore)
+Worker::Worker(Store & store)
     : act(*logger, actRealise)
     , actDerivations(*logger, actBuilds)
     , actSubstitutions(*logger, actCopyPaths)
     , store(store)
-    , evalStore(evalStore)
 {
     /* Debugging: prevent recursive workers. */
     nrLocalBuilds = 0;

src/libstore/build/worker.hh

@@ -110,7 +110,6 @@ public:
     bool checkMismatch;
 
     Store & store;
-    Store & evalStore;
 
     std::unique_ptr<HookInstance> hook;
 
@@ -132,7 +131,7 @@ public:
        it answers with "decline-permanently", we don't try again. */
     bool tryBuildHook = true;
 
-    Worker(Store & store, Store & evalStore);
+    Worker(Store & store);
     ~Worker();
 
     /* Make a goal (with caching). */

src/libstore/ca-specific-schema.sql

@@ -3,19 +3,10 @@
 -- is enabled
 
 create table if not exists Realisations (
-    id integer primary key autoincrement not null,
     drvPath text not null,
     outputName text not null, -- symbolic output id, usually "out"
     outputPath integer not null,
     signatures text, -- space-separated list
+    primary key (drvPath, outputName),
     foreign key (outputPath) references ValidPaths(id) on delete cascade
 );
-
-create index if not exists IndexRealisations on Realisations(drvPath, outputName);
-
-create table if not exists RealisationsRefs (
-    referrer integer not null,
-    realisationReference integer,
-    foreign key (referrer) references Realisations(id) on delete cascade,
-    foreign key (realisationReference) references Realisations(id) on delete restrict
-);

src/libstore/daemon.cc

@@ -243,6 +243,23 @@ struct ClientSettings
     }
 };
 
+static void writeValidPathInfo(
+    ref<Store> store,
+    unsigned int clientVersion,
+    Sink & to,
+    std::shared_ptr<const ValidPathInfo> info)
+{
+    to << (info->deriver ? store->printStorePath(*info->deriver) : "")
+       << info->narHash.to_string(Base16, false);
+    worker_proto::write(*store, to, info->references);
+    to << info->registrationTime << info->narSize;
+    if (GET_PROTOCOL_MINOR(clientVersion) >= 16) {
+        to << info->ultimate
+           << info->sigs
+           << renderContentAddress(info->ca);
+    }
+}
+
 static std::vector<DerivedPath> readDerivedPaths(Store & store, unsigned int clientVersion, Source & from)
 {
     std::vector<DerivedPath> reqs;
@@ -405,7 +422,9 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
             }();
             logger->stopWork();
 
-            pathInfo->write(to, *store, GET_PROTOCOL_MINOR(clientVersion));
+            to << store->printStorePath(pathInfo->path);
+            writeValidPathInfo(store, clientVersion, to, pathInfo);
+
         } else {
             HashType hashAlgo;
             std::string baseName;
@@ -452,21 +471,6 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         break;
     }
 
-    case wopAddMultipleToStore: {
-        bool repair, dontCheckSigs;
-        from >> repair >> dontCheckSigs;
-        if (!trusted && dontCheckSigs)
-            dontCheckSigs = false;
-
-        logger->startWork();
-        FramedSource source(from);
-        store->addMultipleToStore(source,
-            RepairFlag{repair},
-            dontCheckSigs ? NoCheckSigs : CheckSigs);
-        logger->stopWork();
-        break;
-    }
-
     case wopAddTextToStore: {
         string suffix = readString(from);
         string s = readString(from);
@@ -766,7 +770,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         if (info) {
             if (GET_PROTOCOL_MINOR(clientVersion) >= 17)
                 to << 1;
-            info->write(to, *store, GET_PROTOCOL_MINOR(clientVersion), false);
+            writeValidPathInfo(store, clientVersion, to, info);
         } else {
             assert(GET_PROTOCOL_MINOR(clientVersion) >= 17);
             to << 0;
@@ -881,15 +885,10 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
 
     case wopRegisterDrvOutput: {
         logger->startWork();
-        if (GET_PROTOCOL_MINOR(clientVersion) < 31) {
-            auto outputId = DrvOutput::parse(readString(from));
-            auto outputPath = StorePath(readString(from));
-            store->registerDrvOutput(Realisation{
-                .id = outputId, .outPath = outputPath});
-        } else {
-            auto realisation = worker_proto::read(*store, from, Phantom<Realisation>());
-            store->registerDrvOutput(realisation);
-        }
+        auto outputId = DrvOutput::parse(readString(from));
+        auto outputPath = StorePath(readString(from));
+        store->registerDrvOutput(Realisation{
+            .id = outputId, .outPath = outputPath});
         logger->stopWork();
         break;
     }
@@ -899,15 +898,9 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         auto outputId = DrvOutput::parse(readString(from));
         auto info = store->queryRealisation(outputId);
         logger->stopWork();
-        if (GET_PROTOCOL_MINOR(clientVersion) < 31) {
-            std::set<StorePath> outPaths;
-            if (info) outPaths.insert(info->outPath);
-            worker_proto::write(*store, to, outPaths);
-        } else {
-            std::set<Realisation> realisations;
-            if (info) realisations.insert(*info);
-            worker_proto::write(*store, to, realisations);
-        }
+        std::set<StorePath> outPaths;
+        if (info) outPaths.insert(info->outPath);
+        worker_proto::write(*store, to, outPaths);
         break;
     }
 

src/libstore/derivations.cc

@@ -568,7 +568,7 @@ DrvHashModulo hashDerivationModulo(Store & store, const Derivation & drv, bool m
 }
 
 
-std::map<std::string, Hash> staticOutputHashes(Store & store, const Derivation & drv)
+std::map<std::string, Hash> staticOutputHashes(Store& store, const Derivation& drv)
 {
     std::map<std::string, Hash> res;
     std::visit(overloaded {

src/libstore/dummy-store.cc

@@ -43,6 +43,11 @@ struct DummyStore : public virtual DummyStoreConfig, public virtual Store
         RepairFlag repair, CheckSigsFlag checkSigs) override
     { unsupported("addToStore"); }
 
+    StorePath addToStore(const string & name, const Path & srcPath,
+        FileIngestionMethod method, HashType hashAlgo,
+        PathFilter & filter, RepairFlag repair) override
+    { unsupported("addToStore"); }
+
     StorePath addTextToStore(const string & name, const string & s,
         const StorePathSet & references, RepairFlag repair) override
     { unsupported("addTextToStore"); }

src/libstore/gc.cc

@@ -775,7 +775,7 @@ void LocalStore::collectGarbage(const GCOptions & options, GCResults & results)
 
         try {
 
-            AutoCloseDir dir(opendir(realStoreDir.get().c_str()));
+            AutoCloseDir dir(opendir(realStoreDir.c_str()));
             if (!dir) throw SysError("opening directory '%1%'", realStoreDir);
 
             /* Read the store and immediately delete all paths that
@@ -856,7 +856,7 @@ void LocalStore::autoGC(bool sync)
             return std::stoll(readFile(*fakeFreeSpaceFile));
 
         struct statvfs st;
-        if (statvfs(realStoreDir.get().c_str(), &st))
+        if (statvfs(realStoreDir.c_str(), &st))
             throw SysError("getting filesystem info about '%s'", realStoreDir);
 
         return (uint64_t) st.f_bavail * st.f_frsize;

src/libstore/globals.hh

@@ -956,9 +956,6 @@ public:
           resolves to a different location from that of the build machine. You
           can enable this setting if you are sure you're not going to do that.
         )"};
-
-    Setting<bool> useRegistries{this, true, "use-registries",
-        "Whether to use flake registries to resolve flake references."};
 };
 
 

src/libstore/legacy-ssh-store.cc

@@ -267,11 +267,8 @@ public:
         return status;
     }
 
-    void buildPaths(const std::vector<DerivedPath> & drvPaths, BuildMode buildMode, std::shared_ptr<Store> evalStore) override
+    void buildPaths(const std::vector<DerivedPath> & drvPaths, BuildMode buildMode) override
     {
-        if (evalStore && evalStore.get() != this)
-            throw Error("building on an SSH store is incompatible with '--eval-store'");
-
         auto conn(connections->get());
 
         conn->to << cmdBuildPaths;

src/libstore/local-fs-store.hh

@@ -18,9 +18,6 @@ struct LocalFSStoreConfig : virtual StoreConfig
     const PathSetting logDir{(StoreConfig*) this, false,
         rootDir != "" ? rootDir + "/nix/var/log/nix" : settings.nixLogDir,
         "log", "directory where Nix will store state"};
-    const PathSetting realStoreDir{(StoreConfig*) this, false,
-        rootDir != "" ? rootDir + "/nix/store" : storeDir, "real",
-        "physical path to the Nix store"};
 };
 
 class LocalFSStore : public virtual LocalFSStoreConfig, public virtual Store
@@ -37,7 +34,7 @@ public:
     /* Register a permanent GC root. */
     Path addPermRoot(const StorePath & storePath, const Path & gcRoot);
 
-    virtual Path getRealStoreDir() { return realStoreDir; }
+    virtual Path getRealStoreDir() { return storeDir; }
 
     Path toRealPath(const Path & storePath) override
     {

src/libstore/local-store.cc

@@ -53,15 +53,12 @@ struct LocalStore::State::Stmts {
     SQLiteStmt InvalidatePath;
     SQLiteStmt AddDerivationOutput;
     SQLiteStmt RegisterRealisedOutput;
-    SQLiteStmt UpdateRealisedOutput;
     SQLiteStmt QueryValidDerivers;
     SQLiteStmt QueryDerivationOutputs;
     SQLiteStmt QueryRealisedOutput;
     SQLiteStmt QueryAllRealisedOutputs;
     SQLiteStmt QueryPathFromHashPart;
     SQLiteStmt QueryValidPaths;
-    SQLiteStmt QueryRealisationReferences;
-    SQLiteStmt AddRealisationReference;
 };
 
 int getSchema(Path schemaPath)
@@ -79,7 +76,7 @@ int getSchema(Path schemaPath)
 
 void migrateCASchema(SQLite& db, Path schemaPath, AutoCloseFD& lockFd)
 {
-    const int nixCASchemaVersion = 2;
+    const int nixCASchemaVersion = 1;
     int curCASchema = getSchema(schemaPath);
     if (curCASchema != nixCASchemaVersion) {
         if (curCASchema > nixCASchemaVersion) {
@@ -97,39 +94,7 @@ void migrateCASchema(SQLite& db, Path schemaPath, AutoCloseFD& lockFd)
               #include "ca-specific-schema.sql.gen.hh"
                 ;
             db.exec(schema);
-            curCASchema = nixCASchemaVersion;
         }
-
-        if (curCASchema < 2) {
-            SQLiteTxn txn(db);
-            // Ugly little sql dance to add a new `id` column and make it the primary key
-            db.exec(R"(
-                create table Realisations2 (
-                    id integer primary key autoincrement not null,
-                    drvPath text not null,
-                    outputName text not null, -- symbolic output id, usually "out"
-                    outputPath integer not null,
-                    signatures text, -- space-separated list
-                    foreign key (outputPath) references ValidPaths(id) on delete cascade
-                );
-                insert into Realisations2 (drvPath, outputName, outputPath, signatures)
-                    select drvPath, outputName, outputPath, signatures from Realisations;
-                drop table Realisations;
-                alter table Realisations2 rename to Realisations;
-            )");
-            db.exec(R"(
-                create index if not exists IndexRealisations on Realisations(drvPath, outputName);
-
-                create table if not exists RealisationsRefs (
-                    referrer integer not null,
-                    realisationReference integer,
-                    foreign key (referrer) references Realisations(id) on delete cascade,
-                    foreign key (realisationReference) references Realisations(id) on delete restrict
-                );
-            )");
-            txn.commit();
-        }
-
         writeFile(schemaPath, fmt("%d", nixCASchemaVersion));
         lockFile(lockFd.get(), ltRead, true);
     }
@@ -141,6 +106,9 @@ LocalStore::LocalStore(const Params & params)
     , LocalStoreConfig(params)
     , Store(params)
     , LocalFSStore(params)
+    , realStoreDir_{this, false, rootDir != "" ? rootDir + "/nix/store" : storeDir, "real",
+        "physical path to the Nix store"}
+    , realStoreDir(realStoreDir_)
     , dbDir(stateDir + "/db")
     , linksDir(realStoreDir + "/.links")
     , reservedPath(dbDir + "/reserved")
@@ -185,13 +153,13 @@ LocalStore::LocalStore(const Params & params)
             printError("warning: the group '%1%' specified in 'build-users-group' does not exist", settings.buildUsersGroup);
         else {
             struct stat st;
-            if (stat(realStoreDir.get().c_str(), &st))
+            if (stat(realStoreDir.c_str(), &st))
                 throw SysError("getting attributes of path '%1%'", realStoreDir);
 
             if (st.st_uid != 0 || st.st_gid != gr->gr_gid || (st.st_mode & ~S_IFMT) != perm) {
-                if (chown(realStoreDir.get().c_str(), 0, gr->gr_gid) == -1)
+                if (chown(realStoreDir.c_str(), 0, gr->gr_gid) == -1)
                     throw SysError("changing ownership of path '%1%'", realStoreDir);
-                if (chmod(realStoreDir.get().c_str(), perm) == -1)
+                if (chmod(realStoreDir.c_str(), perm) == -1)
                     throw SysError("changing permissions on path '%1%'", realStoreDir);
             }
         }
@@ -342,22 +310,13 @@ LocalStore::LocalStore(const Params & params)
     if (settings.isExperimentalFeatureEnabled("ca-derivations")) {
         state->stmts->RegisterRealisedOutput.create(state->db,
             R"(
-                insert into Realisations (drvPath, outputName, outputPath, signatures)
+                insert or replace into Realisations (drvPath, outputName, outputPath, signatures)
                 values (?, ?, (select id from ValidPaths where path = ?), ?)
                 ;
             )");
-        state->stmts->UpdateRealisedOutput.create(state->db,
-            R"(
-                update Realisations
-                    set signatures = ?
-                where
-                    drvPath = ? and
-                    outputName = ?
-                ;
-            )");
         state->stmts->QueryRealisedOutput.create(state->db,
             R"(
-                select Realisations.id, Output.path, Realisations.signatures from Realisations
+                select Output.path, Realisations.signatures from Realisations
                     inner join ValidPaths as Output on Output.id = Realisations.outputPath
                     where drvPath = ? and outputName = ?
                     ;
@@ -369,19 +328,6 @@ LocalStore::LocalStore(const Params & params)
                     where drvPath = ?
                     ;
             )");
-        state->stmts->QueryRealisationReferences.create(state->db,
-            R"(
-                select drvPath, outputName from Realisations
-                    join RealisationsRefs on realisationReference = Realisations.id
-                    where referrer = ?;
-            )");
-        state->stmts->AddRealisationReference.create(state->db,
-            R"(
-                insert or replace into RealisationsRefs (referrer, realisationReference)
-                values (
-                    (select id from Realisations where drvPath = ? and outputName = ?),
-                    (select id from Realisations where drvPath = ? and outputName = ?));
-            )");
     }
 }
 
@@ -491,14 +437,14 @@ void LocalStore::makeStoreWritable()
     if (getuid() != 0) return;
     /* Check if /nix/store is on a read-only mount. */
     struct statvfs stat;
-    if (statvfs(realStoreDir.get().c_str(), &stat) != 0)
+    if (statvfs(realStoreDir.c_str(), &stat) != 0)
         throw SysError("getting info about the Nix store mount point");
 
     if (stat.f_flag & ST_RDONLY) {
         if (unshare(CLONE_NEWNS) == -1)
             throw SysError("setting up a private mount namespace");
 
-        if (mount(0, realStoreDir.get().c_str(), "none", MS_REMOUNT | MS_BIND, 0) == -1)
+        if (mount(0, realStoreDir.c_str(), "none", MS_REMOUNT | MS_BIND, 0) == -1)
             throw SysError("remounting %1% writable", realStoreDir);
     }
 #endif
@@ -718,54 +664,14 @@ void LocalStore::registerDrvOutput(const Realisation & info, CheckSigsFlag check
 void LocalStore::registerDrvOutput(const Realisation & info)
 {
     settings.requireExperimentalFeature("ca-derivations");
+    auto state(_state.lock());
     retrySQLite<void>([&]() {
-        auto state(_state.lock());
-        if (auto oldR = queryRealisation_(*state, info.id)) {
-            if (info.isCompatibleWith(*oldR)) {
-                auto combinedSignatures = oldR->signatures;
-                combinedSignatures.insert(info.signatures.begin(),
-                    info.signatures.end());
-                state->stmts->UpdateRealisedOutput.use()
-                    (concatStringsSep(" ", combinedSignatures))
-                    (info.id.strHash())
-                    (info.id.outputName)
-                    .exec();
-            } else {
-                throw Error("Trying to register a realisation of '%s', but we already "
-                            "have another one locally.\n"
-                            "Local:  %s\n"
-                            "Remote: %s",
-                    info.id.to_string(),
-                    printStorePath(oldR->outPath),
-                    printStorePath(info.outPath)
-                );
-            }
-        } else {
-            state->stmts->RegisterRealisedOutput.use()
-                (info.id.strHash())
-                (info.id.outputName)
-                (printStorePath(info.outPath))
-                (concatStringsSep(" ", info.signatures))
-                .exec();
-        }
-        for (auto & [outputId, depPath] : info.dependentRealisations) {
-            auto localRealisation = queryRealisationCore_(*state, outputId);
-            if (!localRealisation)
-                throw Error("unable to register the derivation '%s' as it "
-                            "depends on the non existent '%s'",
-                    info.id.to_string(), outputId.to_string());
-            if (localRealisation->second.outPath != depPath)
-                throw Error("unable to register the derivation '%s' as it "
-                            "depends on a realisation of '%s' that doesn’t"
-                            "match what we have locally",
-                    info.id.to_string(), outputId.to_string());
-            state->stmts->AddRealisationReference.use()
-                (info.id.strHash())
-                (info.id.outputName)
-                (outputId.strHash())
-                (outputId.outputName)
-                .exec();
-        }
+        state->stmts->RegisterRealisedOutput.use()
+            (info.id.strHash())
+            (info.id.outputName)
+            (printStorePath(info.outPath))
+            (concatStringsSep(" ", info.signatures))
+            .exec();
     });
 }
 
@@ -1776,69 +1682,23 @@ void LocalStore::createUser(const std::string & userName, uid_t userId)
     }
 }
 
-std::optional<std::pair<int64_t, Realisation>> LocalStore::queryRealisationCore_(
-        LocalStore::State & state,
-        const DrvOutput & id)
-{
-    auto useQueryRealisedOutput(
-            state.stmts->QueryRealisedOutput.use()
-                (id.strHash())
-                (id.outputName));
-    if (!useQueryRealisedOutput.next())
-        return std::nullopt;
-    auto realisationDbId = useQueryRealisedOutput.getInt(0);
-    auto outputPath = parseStorePath(useQueryRealisedOutput.getStr(1));
-    auto signatures =
-        tokenizeString<StringSet>(useQueryRealisedOutput.getStr(2));
-
-    return {{
-        realisationDbId,
-        Realisation{
-            .id = id,
-            .outPath = outputPath,
-            .signatures = signatures,
-        }
-    }};
-}
-
-std::optional<const Realisation> LocalStore::queryRealisation_(
-            LocalStore::State & state,
-            const DrvOutput & id)
-{
-    auto maybeCore = queryRealisationCore_(state, id);
-    if (!maybeCore)
-        return std::nullopt;
-    auto [realisationDbId, res] = *maybeCore;
-
-    std::map<DrvOutput, StorePath> dependentRealisations;
-    auto useRealisationRefs(
-        state.stmts->QueryRealisationReferences.use()
-            (realisationDbId));
-    while (useRealisationRefs.next()) {
-        auto depId = DrvOutput {
-            Hash::parseAnyPrefixed(useRealisationRefs.getStr(0)),
-            useRealisationRefs.getStr(1),
-        };
-        auto dependentRealisation = queryRealisationCore_(state, depId);
-        assert(dependentRealisation); // Enforced by the db schema
-        auto outputPath = dependentRealisation->second.outPath;
-        dependentRealisations.insert({depId, outputPath});
-    }
-
-    res.dependentRealisations = dependentRealisations;
-
-    return { res };
-}
-
-std::optional<const Realisation>
-LocalStore::queryRealisation(const DrvOutput & id)
-{
-    return retrySQLite<std::optional<const Realisation>>([&]() {
+std::optional<const Realisation> LocalStore::queryRealisation(
+    const DrvOutput& id) {
+    typedef std::optional<const Realisation> Ret;
+    return retrySQLite<Ret>([&]() -> Ret {
         auto state(_state.lock());
-        return queryRealisation_(*state, id);
+        auto use(state->stmts->QueryRealisedOutput.use()(id.strHash())(
+            id.outputName));
+        if (!use.next())
+            return std::nullopt;
+        auto outputPath = parseStorePath(use.getStr(0));
+        auto signatures = tokenizeString<StringSet>(use.getStr(1));
+        return Ret{Realisation{
+            .id = id, .outPath = outputPath, .signatures = signatures}};
     });
 }
 
+
 FixedOutputHash LocalStore::hashCAPath(
     const FileIngestionMethod & method, const HashType & hashType,
     const StorePath & path)

src/libstore/local-store.hh

@@ -83,6 +83,9 @@ private:
 
 public:
 
+    PathSetting realStoreDir_;
+
+    const Path realStoreDir;
     const Path dbDir;
     const Path linksDir;
     const Path reservedPath;
@@ -203,8 +206,6 @@ public:
     void registerDrvOutput(const Realisation & info, CheckSigsFlag checkSigs) override;
     void cacheDrvOutputMapping(State & state, const uint64_t deriver, const string & outputName, const StorePath & output);
 
-    std::optional<const Realisation> queryRealisation_(State & state, const DrvOutput & id);
-    std::optional<std::pair<int64_t, Realisation>> queryRealisationCore_(State & state, const DrvOutput & id);
     std::optional<const Realisation> queryRealisation(const DrvOutput&) override;
 
 private:
@@ -278,6 +279,8 @@ private:
     void signPathInfo(ValidPathInfo & info);
     void signRealisation(Realisation &);
 
+    Path getRealStoreDir() override { return realStoreDir; }
+
     void createUser(const std::string & userName, uid_t userId) override;
 
     // XXX: Make a generic `Store` method

src/libstore/local.mk

@@ -8,12 +8,12 @@ libstore_SOURCES := $(wildcard $(d)/*.cc $(d)/builtins/*.cc $(d)/build/*.cc)
 
 libstore_LIBS = libutil
 
-libstore_LDFLAGS = $(SQLITE3_LIBS) $(LIBCURL_LIBS) $(SODIUM_LIBS) -pthread
-ifdef HOST_LINUX
+libstore_LDFLAGS = $(SQLITE3_LIBS) -lbz2 $(LIBCURL_LIBS) $(SODIUM_LIBS) -pthread
+ifeq ($(OS), Linux)
  libstore_LDFLAGS += -ldl
 endif
 
-ifdef HOST_DARWIN
+ifeq ($(OS), Darwin)
 libstore_FILES = sandbox-defaults.sb sandbox-minimal.sb sandbox-network.sb
 endif
 
@@ -23,7 +23,7 @@ ifeq ($(ENABLE_S3), 1)
 	libstore_LDFLAGS += -laws-cpp-sdk-transfer -laws-cpp-sdk-s3 -laws-cpp-sdk-core
 endif
 
-ifdef HOST_SOLARIS
+ifeq ($(OS), SunOS)
 	libstore_LDFLAGS += -lsocket
 endif
 
@@ -60,7 +60,7 @@ $(d)/build.cc:
 
 clean-files += $(d)/schema.sql.gen.hh $(d)/ca-specific-schema.sql.gen.hh
 
-$(eval $(call install-file-in, $(d)/nix-store.pc, $(libdir)/pkgconfig, 0644))
+$(eval $(call install-file-in, $(d)/nix-store.pc, $(prefix)/lib/pkgconfig, 0644))
 
 $(foreach i, $(wildcard src/libstore/builtins/*.hh), \
   $(eval $(call install-file-in, $(i), $(includedir)/nix/builtins, 0644)))

src/libstore/machines.cc

@@ -16,18 +16,13 @@ Machine::Machine(decltype(storeUri) storeUri,
     decltype(mandatoryFeatures) mandatoryFeatures,
     decltype(sshPublicHostKey) sshPublicHostKey) :
     storeUri(
-        // Backwards compatibility: if the URI is schemeless, is not a path,
-        // and is not one of the special store connection words, prepend
-        // ssh://.
+        // Backwards compatibility: if the URI is a hostname,
+        // prepend ssh://.
         storeUri.find("://") != std::string::npos
-        || storeUri.find("/") != std::string::npos
-        || storeUri == "auto"
-        || storeUri == "daemon"
-        || storeUri == "local"
-        || hasPrefix(storeUri, "auto?")
-        || hasPrefix(storeUri, "daemon?")
-        || hasPrefix(storeUri, "local?")
-        || hasPrefix(storeUri, "?")
+        || hasPrefix(storeUri, "local")
+        || hasPrefix(storeUri, "remote")
+        || hasPrefix(storeUri, "auto")
+        || hasPrefix(storeUri, "/")
         ? storeUri
         : "ssh://" + storeUri),
     systemTypes(systemTypes),