anchor.diff:    qpid-python = buildPythonPackage rec {
       name = "qpid-python-${version}";
       version = "0.32";
  +    disabled = isPy3k;  # not supported
   
       src = pkgs.fetchurl {
         url = "http://www.us.apache.org/dist/qpid/${version}/${name}.tar.gz";
  
positive.code:       testtools testrepository mock
      ];
  
      meta = with stdenv.lib; {
        description = "Python bindings to the OpenStack Object Storage API";
        homepage = "http://www.openstack.org/";
  
negative.code:   keystoneauth1 = buildPythonPackage rec {
      name = "keystoneauth1-${version}";
      version = "1.1.0";
      disabled = isPyPy; # a test fails
  
      src = pkgs.fetchurl {
        url = "https://pypi.python.org/packages/source/k/keystoneauth1/${name}.tar.gz";
  