nixpkgs/nixos/tests/nixos-test-driver/busybox.nix

{
  name = "Test that basic tests work when busybox is installed";

  nodes = {
    machine = (
      { pkgs, ... }:
      {
        environment.systemPackages = [
          pkgs.busybox
        ];
      }
    );
  };

  testScript = ''
    start_all()
    machine.wait_for_unit("multi-user.target")
  '';
}