Merge pull request #10995 from NixOS/meson-remove-symlink-hack

Remove symlink hack from meson packaging

packaging/dependencies.nix

@@ -10,6 +10,33 @@
   stdenv,
   versionSuffix,
 }:
+let
+  inherit (pkgs) lib;
+
+  localSourceLayer = finalAttrs: prevAttrs:
+    let
+      root = ../.;
+      workDirPath =
+        # Ideally we'd pick finalAttrs.workDir, but for now `mkDerivation` has
+        # the requirement that everything except passthru and meta must be
+        # serialized by mkDerivation, which doesn't work for this.
+        prevAttrs.workDir;
+
+      workDirSubpath = lib.path.removePrefix root workDirPath;
+      sources = assert prevAttrs.fileset._type == "fileset"; prevAttrs.fileset;
+      src = lib.fileset.toSource { fileset = sources; inherit root; };
+
+    in
+    {
+      sourceRoot = "${src.name}/" + workDirSubpath;
+      inherit src;
+
+      # Clear what `derivation` can't/shouldn't serialize; see prevAttrs.workDir.
+      fileset = null;
+      workDir = null;
+    };
+
+in
 scope: {
   inherit stdenv versionSuffix;
 
@@ -55,4 +82,6 @@ scope: {
       CONFIG_ASH_TEST y
     '';
   });
+
+  mkMesonDerivation = f: stdenv.mkDerivation (lib.extends localSourceLayer f);
 }

src/libutil/package.nix

@@ -1,5 +1,6 @@
 { lib
 , stdenv
+, mkMesonDerivation
 , releaseTools
 
 , meson
@@ -38,22 +39,22 @@ let
     else stdenv.mkDerivation;
 in
 
-mkDerivation (finalAttrs: {
+mkMesonDerivation (finalAttrs: {
   pname = "nix-util";
   inherit version;
 
-  src = fileset.toSource {
-    root = ./.;
-    fileset = fileset.unions [
-      ./meson.build
-      ./meson.options
-      ./linux/meson.build
-      ./unix/meson.build
-      ./windows/meson.build
-      (fileset.fileFilter (file: file.hasExt "cc") ./.)
-      (fileset.fileFilter (file: file.hasExt "hh") ./.)
-    ];
-  };
+  workDir = ./.;
+  fileset = fileset.unions [
+    ../../.version
+    ./.version
+    ./meson.build
+    ./meson.options
+    ./linux/meson.build
+    ./unix/meson.build
+    ./windows/meson.build
+    (fileset.fileFilter (file: file.hasExt "cc") ./.)
+    (fileset.fileFilter (file: file.hasExt "hh") ./.)
+  ];
 
   outputs = [ "out" "dev" ];
 
@@ -80,9 +81,10 @@ mkDerivation (finalAttrs: {
   disallowedReferences = [ boost ];
 
   preConfigure =
-    # "Inline" .version so it's not a symlink, and includes the suffix
+    # TODO: change release process to add `pre` in `.version`, remove it before tagging, and restore after.
     ''
-      echo ${version} > .version
+      chmod u+w ./.version
+      echo ${version} > ../../.version
     ''
     # Copy some boost libraries so we don't get all of Boost in our
     # closure. https://github.com/NixOS/nixpkgs/issues/45462