anchor.diff:  { stdenv, fetchurl, automake, pkgconfig
   , cups, zlib, libjpeg, libusb1, pythonPackages, saneBackends, dbus
  -, polkit, qtSupport ? true, qt4, pythonDBus, pyqt4, net_snmp
  -, withPlugin ? false, substituteAll
  +, polkit, qtSupport ? true, qt4, pyqt4, net_snmp
  +, withPlugin ? false, substituteAll, makeWrapper
   }:
   
   let
  
positive.code:     ] ++ stdenv.lib.optional qtSupport qt4;
  
    pythonPath = with pythonPackages; [
        pillow
        pythonDBus
        pygobject
        recursivePthLoader
        reportlab
  
negative.code: 
    postInstall =
      ''
        # Wrap the user-facing Python scripts in /bin without turning the ones
        # in /share into shell scripts (they need to be importable).
        # Complicated by the fact that /bin contains just symlinks to /share.
        for bin in $out/bin/*; do
          py=`readlink -m $bin`
          rm $bin
          cp $py $bin
          wrapPythonProgramsIn $bin "$out $pythonPath"
          sed -i "s@$(dirname $bin)/[^ ]*@$py@g" $bin
        done
  
        # Remove originals. Knows a little too much about wrapPythonProgramsIn.
        rm -f $out/bin/.*-wrapped
      ''
      + (stdenv.lib.optionalString withPlugin
      (let hplip_arch =
  