anchor.diff:  
     pygtk = import ../development/python-modules/pygtk {
       inherit (pkgs) fetchurl stdenv pkgconfig gtk;
  -    inherit python buildPythonPackage pygobject pycairo;
  -  };
  +    inherit python buildPythonPackage pygobject pycairo isPy3k;
  +  }; 
   
     # XXX: how can we get an override here?
     #pyGtkGlade = pygtk.override {
  
positive.code: 
    oauth2 = buildPythonPackage (rec {
      name = "oauth2-1.5.211";
  
      src = fetchurl {
        url = "http://pypi.python.org/packages/source/o/oauth2/oauth2-1.5.211.tar.gz";
  
negative.code:   libarchive = buildPythonPackage rec {
      version = "3.1.2-1";
      name = "libarchive-${version}";
      disabled = isPy3k;
  
      src = fetchurl {
        url = "http://python-libarchive.googlecode.com/files/python-libarchive-${version}.tar.gz";
  