anchor.diff:      sha256 = "11drd6ixx75q3w12am3z1npwllq1kxnhbxv0npng92c69kn291zs";
     };
   
  -  buildInputs = [ glib polkit systemd python gobjectIntrospection vala_0_38 ]
  +  buildInputs = [ glib polkit python gobjectIntrospection vala_0_38 ]
  +                  ++ lib.optional enableSystemd systemd
                     ++ lib.optional enableBashCompletion bash-completion;
     propagatedBuildInputs = [ sqlite nix boost ];
     nativeBuildInputs = [ intltool pkgconfig autoreconfHook autoconf-archive gtk-doc ];
  
positive.code:   '';
  
    configureFlags = [
      "--enable-systemd"
      "--disable-dummy"
      "--disable-cron"
      "--disable-introspection"
  
negative.code: { stdenv, fetchFromGitHub, lib
  , intltool, glib, pkgconfig, polkit, python, sqlite
  , gobjectIntrospection, vala_0_38, gtk-doc, autoreconfHook, autoconf-archive
  # TODO: set enableNixBackend to true, as soon as it builds
  , nix, enableNixBackend ? false, boost
  , enableCommandNotFound ? false
  , enableBashCompletion ? false, bash-completion ? null
  , enableSystemd ? stdenv.isLinux, systemd }:
  
  stdenv.mkDerivation rec {
    name = "packagekit-${version}";
  