applyPatches: unbreak support for path-like sources (#405148)

      let

        keepAttrs = names: lib.filterAttrs (name: val: lib.elem name names);

        # enables tools like nix-update to determine what src attributes to replace

        extraPassthru = keepAttrs [

        extraPassthru = lib.optionalAttrs (lib.isAttrs src) (

          keepAttrs [

            "rev"

            "tag"

            "url"

            "outputHash"

        ] src;

          ] src

        );

      in

      stdenvNoCC.mkDerivation (

        {