diff --git a/pkgs/by-name/gn/gn/package.nix b/pkgs/by-name/gn/gn/package.nix
index a9cb3782531a..54764e338e85 100644
--- a/pkgs/by-name/gn/gn/package.nix
+++ b/pkgs/by-name/gn/gn/package.nix
@@ -3,38 +3,30 @@
   lib,
   fetchgit,
   cctools,
-  writeText,
   ninja,
   python3,
 }:
-let
-  # Note: Please use the recommended version for Chromium stable, i.e. from
-  # <nixpkgs>/pkgs/applications/networking/browsers/chromium/info.json
-  rev = "85cc21e94af590a267c1c7a47020d9b420f8a033";
-  revNum = "2233"; # git describe $rev --match initial-commit | cut -d- -f3
-  version = "2025-04-28";
-  sha256 = "sha256-+nKP2hBUKIqdNfDz1vGggXSdCuttOt0GwyGUQ3Z1ZHI=";
 
-  revShort = builtins.substring 0 7 rev;
-  lastCommitPosition = writeText "last_commit_position.h" ''
-    #ifndef OUT_LAST_COMMIT_POSITION_H_
-    #define OUT_LAST_COMMIT_POSITION_H_
-
-    #define LAST_COMMIT_POSITION_NUM ${revNum}
-    #define LAST_COMMIT_POSITION "${revNum} (${revShort})"
-
-    #endif  // OUT_LAST_COMMIT_POSITION_H_
-  '';
-
-in
 stdenv.mkDerivation {
   pname = "gn-unstable";
-  inherit version;
+  version = "2025-04-28";
 
   src = fetchgit {
     # Note: The TAR-Archives (+archive/${rev}.tar.gz) are not deterministic!
     url = "https://gn.googlesource.com/gn";
-    inherit rev sha256;
+    # Note: Please use the recommended version for Chromium stable, i.e. from
+    # <nixpkgs>/pkgs/applications/networking/browsers/chromium/info.json
+    rev = "85cc21e94af590a267c1c7a47020d9b420f8a033";
+    hash = "sha256-SYpWYvGGNLMZPR1LdKKgubbv+4QcxRw8EYp7cNI5wQQ=";
+    leaveDotGit = true;
+    deepClone = true;
+    postFetch = ''
+      cd "$out"
+      mkdir .nix-files
+      git rev-parse --short=12 HEAD > .nix-files/REV_SHORT
+      git describe --match initial-commit | cut -d- -f3 > .nix-files/REV_NUM
+      find "$out" -name .git -print0 | xargs -0 rm -rf
+    '';
   };
 
   nativeBuildInputs = [
@@ -50,9 +42,20 @@ stdenv.mkDerivation {
   # cc1plus: error: '-Wformat-security' ignored without '-Wformat' [-Werror=format-security]
   hardeningDisable = [ "format" ];
 
-  buildPhase = ''
+  configurePhase = ''
     python build/gen.py --no-last-commit-position
-    ln -s ${lastCommitPosition} out/last_commit_position.h
+    cat > out/last_commit_position.h << EOF
+    #ifndef OUT_LAST_COMMIT_POSITION_H_
+    #define OUT_LAST_COMMIT_POSITION_H_
+
+    #define LAST_COMMIT_POSITION_NUM $(<.nix-files/REV_NUM)
+    #define LAST_COMMIT_POSITION "$(<.nix-files/REV_NUM) ($(<.nix-files/REV_SHORT))"
+
+    #endif  // OUT_LAST_COMMIT_POSITION_H_
+    EOF
+  '';
+
+  buildPhase = ''
     ninja -j $NIX_BUILD_CORES -C out gn
   '';