1 files changed, 23 insertions, 0 deletions
diff --git a/pkgs/build-support/fetchgitlocal/default.nix b/pkgs/build-support/fetchgitlocal/default.nix
new file mode 100644
index 000000000000..43fc4b1179d7
--- /dev/null
+++ b/pkgs/build-support/fetchgitlocal/default.nix
@@ -0,0 +1,23 @@
+{ runCommand, git, nix }: src:
+
+let hash = import (runCommand "head-hash.nix"
+  { dummy = builtins.currentTime;
+    preferLocalBuild = true; }
+''
+  cd ${toString src}
+  (${git}/bin/git show && ${git}/bin/git diff) > $out
+  hash=$(${nix}/bin/nix-hash $out)
+  echo "\"$hash\"" > $out
+''); in
+
+runCommand "local-git-export"
+  { dummy = hash;
+    preferLocalBuild = true; }
+''
+  cd ${toString src}
+  mkdir -p "$out"
+  for file in $(${git}/bin/git ls-files); do
+    mkdir -p "$out/$(dirname $file)"
+    cp -d $file "$out/$file" || true # don't fail when trying to copy a directory
+  done
+''