anchor.diff:  
     tools = dbus_drv "tools" "tools bus" {
       preBuild = makeInternalLib;
  -    buildInputs = buildInputsX ++ systemdOrEmpty ++ [ libs ];
  +    buildInputs = buildInputsX ++ [ libsystemd libs ];
       NIX_CFLAGS_LINK = "-Wl,--as-needed " + "-ldbus-1";
   
       # don't provide another dbus-1.pc (with incorrect include and link dirs),
  
positive.code:     };
  
      patches = [
          ./ignore-missing-includedirs.patch
          ./ucred-dirty-hack.patch
          ./no-create-dirs.patch
        ]
        ++ lib.optional (stdenv.isLinux) ./implement-getgrouplist.patch
        ;
  
      # build only the specified subdirs
      postPatch = "sed '/SUBDIRS/s/=.*/=" + subdirs + "/' -i Makefile.am\n"
  
negative.code: { stdenv, fetchurl, pkgconfig, autoreconfHook
  , expat, libsystemd, glib, dbus_glib, python
  , xorg ? null, x11Support ? true }:
  
  assert x11Support -> xorg != null;
  
  