anchor.diff:  
     meta = with lib; {
       description = "A backport of the new features added to the unittest testing framework";
  -    homepage = "https://pypi.python.org/pypi/unittest2";
  +    homepage = "https://pypi.org/project/unittest2/";
       license = licenses.bsd0;
  +    # AttributeError: module 'collections' has no attribute 'MutableMapping'
  +    broken = pythonAtLeast "3.10";
     };
  -
   }
  
positive.code: , fetchPypi
  , six
  , traceback2
  }:
  
  buildPythonPackage rec {
  
negative.code: 
    propagatedBuildInputs = [ six traceback2 ];
  
    # 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
      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
  