nixos-lib/lib/types.nix

{ lib, myLib }:
with lib;
{
  package' = types.package // {
    merge =
      loc: defs:
      let
        res = mergeDefaultOption loc defs;
      in
      if builtins.isPath res || (builtins.isString res && !builtins.hasContext res) then
        toDerivation res
      else
        res;
  };
}