load database with checksum again but do the same in disko-install

disko-install

@@ -207,11 +207,13 @@ main() {
     --arg diskMappings "$(serialiaseArrayToNix diskMappings)" \
     --argstr extraSystemConfig "$extraSystemConfig" \
     -A installToplevel \
+    -A closureInfo \
     -A "$diskoAttr")
 
   IFS=$'\n' mapfile -t artifacts <<<"$outputs"
   nixos_system=${artifacts[0]}
-  disko_script=${artifacts[1]}
+  closure_info=${artifacts[1]}
+  disko_script=${artifacts[2]}
 
   if [[ -n ${dry_run-} ]]; then
     echo "Would run: $disko_script"
@@ -227,6 +229,23 @@ main() {
     cp -ar "$source" "$mountPoint/$destination"
   done
 
+  # nix copy uses up a lot of memory and we work around issues with incorrect checksums in our store
+  # that can be caused by using closureInfo in combination with multiple builders and non-deterministic builds.
+  # Therefore if we have a blank store, we copy the store paths and registration from the closureInfo.
+  if [[ ! -d "${mountPoint}/nix/store" ]]; then
+    export NIX_STATE_DIR=${mountPoint}/nix/var/nix
+    echo "Copying store paths" >&2
+
+    if [ -t 1 ]; then
+      xargs -I% xcp --recursive % "${mountPoint}/nix/store" < "${closure_info}/store-paths"
+    else
+      xargs -I% xcp --recursive --no-progress % "${mountPoint}/nix/store" < "${closure_info}/store-paths"
+    fi
+    echo "Loading nix database" >&2
+    nix-store --load-db < "${closure_info}/registration"
+    unset NIX_STATE_DIR
+  fi
+
   nixos-install --no-root-password --system "$nixos_system" --root "$mountPoint"
 }
 

disko-install.nix

@@ -1,11 +1,16 @@
-{ stdenvNoCC, makeWrapper, lib }:
+{
+  stdenvNoCC,
+  makeWrapper,
+  lib,
+  coreutils,
+  xcp,
+  nixos-install-tools,
+}:
 
 stdenvNoCC.mkDerivation {
   name = "disko-install";
   src = ./.;
-  nativeBuildInputs = [
-    makeWrapper
-  ];
+  nativeBuildInputs = [ makeWrapper ];
   installPhase = ''
     mkdir -p $out/bin $out/share/disko
     cp -r install-cli.nix $out/share/disko
@@ -14,7 +19,14 @@ stdenvNoCC.mkDerivation {
       -e "s|#!/usr/bin/env.*|#!/usr/bin/env bash|" \
       disko-install > $out/bin/disko-install
     chmod 755 $out/bin/disko-install
-    wrapProgram $out/bin/disko-install
+    wrapProgram $out/bin/disko-install \
+      --prefix PATH : "${
+        lib.makeBinPath [
+          coreutils
+          xcp
+          nixos-install-tools
+        ]
+      }"
   '';
   meta = with lib; {
     description = "Disko and nixos-install in one command";

docs/disko-install.md

@@ -197,9 +197,10 @@ Add this to your flake.nix output:
 { pkgs, self, ... }:
 let
   dependencies = [
-    pkgs.stdenv.drvPath
     self.nixosConfigurations.your-machine.config.system.build.toplevel
     self.nixosConfigurations.your-machine.config.system.build.diskoScript
+    self.nixosConfigurations.your-machine.pkgs.stdenv.drvPath
+    (self.nixosConfigurations.your-machine.pkgs.closureInfo { rootPaths = [ ]; }).drvPath
   ] ++ builtins.map (i: i.outPath) (builtins.attrValues self.inputs);
 
   closureInfo = pkgs.closureInfo { rootPaths = dependencies; };

install-cli.nix

@@ -62,5 +62,8 @@ let
 in
 {
   installToplevel = installSystem.config.system.build.toplevel;
+  closureInfo = installSystem.pkgs.closureInfo {
+    rootPaths = [ installSystem.config.system.build.toplevel ];
+  };
   inherit (diskoSystem.config.system.build) formatScript mountScript diskoScript;
 }

lib/closure-info.nix

@@ -1,45 +0,0 @@
-# This is a modified version of the closure-info derivation from nixpkgs.
-# Unlike the original, it does not include hashes in the registration file,
-# which might be incorrect if a build is not binary reproducible.
-
-# This derivation builds two files containing information about the
-# closure of 'rootPaths': $out/store-paths contains the paths in the
-# closure, and $out/registration contains a file suitable for use with
-# "nix-store --register-validity".
-
-{ stdenv, coreutils, jq }:
-
-{ rootPaths }:
-
-assert builtins.langVersion >= 5;
-
-stdenv.mkDerivation {
-  name = "closure-info";
-
-  __structuredAttrs = true;
-
-  exportReferencesGraph.closure = rootPaths;
-
-  preferLocalBuild = true;
-
-  nativeBuildInputs = [ coreutils jq ];
-
-  empty = rootPaths == [];
-
-  buildCommand =
-    ''
-      out=''${outputs[out]}
-
-      mkdir $out
-
-      if [[ -n "$empty" ]]; then
-        echo 0 > $out/total-nar-size
-        touch $out/registration $out/store-paths
-      else
-        jq -r ".closure | map(.narSize) | add" < "$NIX_ATTRS_JSON_FILE" > $out/total-nar-size
-        jq -r '.closure | map([.path, "", (.references | length)] + .references) | add | map("\(.)\n") | add' < "$NIX_ATTRS_JSON_FILE" | head -n -1 > $out/registration
-        jq -r '.closure[].path' < "$NIX_ATTRS_JSON_FILE" > $out/store-paths
-      fi
-
-    '';
-}

lib/make-disk-image.nix

@@ -28,6 +28,7 @@ let
     systemdMinimal
     nix
     util-linux
+    xcp
   ] ++ nixosConfig.config.disko.extraDependencies;
   preVM = ''
     ${lib.concatMapStringsSep "\n" (disk: "truncate -s ${disk.imageSize} ${disk.name}.raw") (lib.attrValues nixosConfig.config.disko.devices.disk)}
@@ -39,7 +40,7 @@ let
     ${extraPostVM}
   '';
 
-  closureInfo = (pkgs.callPackage ./closure-info.nix { }) {
+  closureInfo = pkgs.closureInfo {
     rootPaths = [ systemToInstall.config.system.build.toplevel ];
   };
   partitioner = ''
@@ -63,15 +64,11 @@ let
   installer = ''
     # populate nix db, so nixos-install doesn't complain
     export NIX_STATE_DIR=${systemToInstall.config.disko.rootMountPoint}/nix/var/nix
-    # We have to use fakeroot here, because nix tries to chown files in the original store.
-    # fakeroot will make override all chown calls to no-ops.
-    echo "Registering store paths..."
-    ${pkgs.fakeroot}/bin/fakeroot nix-store --register-validity --reregister < ${closureInfo}/registration
+    nix-store --load-db < "${closureInfo}/registration"
 
     # We copy files with cp because `nix copy` seems to have a large memory leak
-    echo "Copying store paths..."
     mkdir -p ${systemToInstall.config.disko.rootMountPoint}/nix/store
-    xargs cp -r --target-directory=${systemToInstall.config.disko.rootMountPoint}/nix/store < ${closureInfo}/store-paths
+    xargs -I % xcp --recursive % ${systemToInstall.config.disko.rootMountPoint}/nix/store < ${closureInfo}/store-paths
 
     ${systemToInstall.config.system.build.nixos-install}/bin/nixos-install --root ${systemToInstall.config.disko.rootMountPoint} --system ${systemToInstall.config.system.build.toplevel} --keep-going --no-channel-copy -v --no-root-password --option binary-caches ""
     umount -Rv ${systemToInstall.config.disko.rootMountPoint}

tests/disko-install/default.nix

@@ -3,7 +3,8 @@ let
   disko-install = pkgs.callPackage ../../disko-install.nix { };
 
   dependencies = [
-    pkgs.stdenv.drvPath
+    self.nixosConfigurations.testmachine.pkgs.stdenv.drvPath
+    (self.nixosConfigurations.testmachine.pkgs.closureInfo { rootPaths = []; }).drvPath
     self.nixosConfigurations.testmachine.config.system.build.toplevel
     self.nixosConfigurations.testmachine.config.system.build.diskoScript
   ] ++ builtins.map (i: i.outPath) (builtins.attrValues self.inputs);