{ busybox }:
with import ./config.nix;
let

  mkDerivation =
    args:
    derivation (
      {
        inherit system;
        builder = busybox;
        args = [
          "sh"
          "-e"
          args.builder or (builtins.toFile "builder-${args.name}.sh" ''
            if [ -e "$NIX_ATTRS_SH_FILE" ]; then source $NIX_ATTRS_SH_FILE; fi;
            eval "$buildCommand"
          '')
        ];
      }
      // removeAttrs args [
        "builder"
        "meta"
      ]
    )
    // {
      meta = args.meta or { };
    };
in
{

  failing = mkDerivation {
    name = "failing";
    buildCommand = ''
      echo foo > bar
      exit 1
    '';
  };
}