anchor.diff:    doCheck = false;
   
     propagatedBuildInputs = [ msgpack ]
  -    ++ lib.optional (!isPyPy) greenlet
  -    ++ lib.optional (pythonOlder "3.4") trollius;
  +    ++ lib.optional (!isPyPy) greenlet;
   
     meta = {
       description = "Python client for Neovim";
  
positive.code: , nose
  , msgpack
  , greenlet
  , trollius ? null
  , pythonOlder
  , isPyPy
  , pytestrunner
  
negative.code: buildPythonPackage rec {
    pname = "pynvim";
    version = "0.4.3";
    disabled = pythonOlder "3.4";
  
    src = fetchPypi {
      inherit pname version;
  