core/pkgs/build-support/fetchsavannah/default.nix

{ fetchzip, lib }:

lib.makeOverridable (
  # cgit example, snapshot support is optional in cgit
  {
    repo,
    rev,
    name ? "source-savannah.gnu.org-${repo}-${rev}",
    ... # For hash agility
  }@args:
  fetchzip (
    {
      inherit name;
      url = "https://git.savannah.gnu.org/cgit/${repo}.git/snapshot/${repo}-${rev}.tar.gz";
      meta.homepage = "https://git.savannah.gnu.org/cgit/${repo}.git/";
    }
    // removeAttrs args [
      "repo"
      "rev"
    ]
  )
  // {
    inherit rev;
  }
)