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