{ drv ? import ./shell.nix }:
derivation (drv.drvAttrs // {
  name = "${drv.name}-env";
  system = builtins.currentSystem;
  _derivation_original_builder = drv.builder;
  _derivation_original_args = drv.args;
  builder = (import <nix/config.nix>).shell;
  args = [ "-c" "export > $out" ];
})