anchor.diff: -{stdenv, fetchurl, cups, zlib, libjpeg, libusb, python, saneBackends, dbus
  -, pkgconfig, polkit, qtSupport ? true, qt4
  +{stdenv, fetchurl, cups, zlib, libjpeg, libusb, pythonPackages, saneBackends, dbus
  +, pkgconfig, polkit, qtSupport ? true, qt4, pythonDBus, pyqt4
   }:
   
   stdenv.mkDerivation rec {
  
positive.code: 
    prePatch = ''
      sed -i s,/etc/sane.d,$out/etc/sane.d/, Makefile.in
    '';
  
    # --disable-network-build Until we have snmp
  
negative.code:     ";
    '';
  
    postInstall = ''
      wrapPythonPrograms
      '';
  
    buildInputs = [
        libjpeg
        cups
        libusb
        pythonPackages.python
        pythonPackages.wrapPython
        pythonPackages.recursivePthLoader # does not seem to work?
        saneBackends
        dbus
        pkgconfig] ++
      stdenv.lib.optional qtSupport qt4;
  
    pythonPath = with pythonPackages; [
        pythonDBus
        pyqt4
        pygobject
      ];
  
    meta = with stdenv.lib; {
      description = "Print, scan and fax HP drivers for Linux";
  