libutil/package.nix: Remove .version symlink replacement solution

src/libutil/package.nix

@@ -1,5 +1,6 @@
 { lib
 , stdenv
+, mkMesonDerivation
 , releaseTools
 
 , meson
@@ -38,13 +39,14 @@ let
     else stdenv.mkDerivation;
 in
 
-mkDerivation (finalAttrs: {
+mkMesonDerivation (finalAttrs: {
   pname = "nix-util";
   inherit version;
 
-  src = fileset.toSource {
-    root = ./.;
+  workDir = ./.;
   fileset = fileset.unions [
+    ../../.version
+    ./.version
     ./meson.build
     ./meson.options
     ./linux/meson.build
@@ -53,7 +55,6 @@ mkDerivation (finalAttrs: {
     (fileset.fileFilter (file: file.hasExt "cc") ./.)
     (fileset.fileFilter (file: file.hasExt "hh") ./.)
   ];
-  };
 
   outputs = [ "out" "dev" ];
 
@@ -80,13 +81,9 @@ mkDerivation (finalAttrs: {
   disallowedReferences = [ boost ];
 
   preConfigure =
-    # "Inline" .version so it's not a symlink, and includes the suffix
-    ''
-      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
-    + lib.optionalString (!stdenv.hostPlatform.isStatic) (''
+    lib.optionalString (!stdenv.hostPlatform.isStatic) (''
       mkdir -p $out/lib
       cp -pd ${boost}/lib/{libboost_context*,libboost_thread*,libboost_system*} $out/lib
       rm -f $out/lib/*.a