anchor.diff:  
     propagatedBuildInputs = [ six traceback2 ];
   
  -  # # 1.0.0 and up create a circle dependency with traceback2/pbr
  +  # 1.0.0 and up create a circle dependency with traceback2/pbr
     doCheck = false;
   
     postPatch = ''
       # argparse is needed for python < 2.7, which we do not support anymore.
       substituteInPlace setup.py --replace "argparse" ""
   
  -    # # fixes a transient error when collecting tests, see https://bugs.launchpad.net/python-neutronclient/+bug/1508547
  +    # fixes a transient error when collecting tests, see https://bugs.launchpad.net/python-neutronclient/+bug/1508547
       sed -i '510i\        return None, False' unittest2/loader.py
       # https://github.com/pypa/packaging/pull/36
       sed -i 's/version=VERSION/version=str(VERSION)/' setup.py
  
positive.code: 
    meta = with lib; {
      description = "A backport of the new features added to the unittest testing framework";
      homepage = "https://pypi.python.org/pypi/unittest2";
      license = licenses.bsd0;
    };
  
  }
  
negative.code: , fetchPypi
  , six
  , traceback2
  , pythonAtLeast
  }:
  
  buildPythonPackage rec {
  