nix: writeScript without stdenv

writeScript.nix

{ name ? "hello"
, text ? "echo 'Hello World'"
, pkgs ? import <nixpkgs> {}
}:
builtins.derivation {
  inherit name;
  inherit (pkgs) system;
  builder = "${pkgs.busybox}/bin/busybox";
  args = [
    "sh"
    "-c"
    ''
        echo "${text}" > $out
        $builder chmod +x $out
    ''
  ];
}