anchor.diff:  , click-default-group
   , incremental
   , jinja2
  +, mock
   , pytestCheckHook
   , toml
   , twisted
  
positive.code: 
  buildPythonPackage rec {
    pname = "towncrier";
    version = "19.9.0";
  
    src = fetchPypi {
      inherit pname version;
      sha256 = "19916889879353a8863f3de8cb1ef19b305a0b5cfd9d36159d76ca2fef08e9aa";
    };
  
    propagatedBuildInputs = [
  
negative.code: 
    # zope.interface collision
    doCheck = !isPy27;
    checkInputs = [
      git
      mock
      twisted
      pytestCheckHook
    ];
    pythonImportsCheck = [ "towncrier" ];
  
    meta = with lib; {
  