anchor.diff: -{ stdenv, buildPythonPackage, fetchPypi, pytest_3, mock, six, twisted,isPy37 }:
  +{ stdenv, buildPythonPackage, fetchPypi, pytest, mock, six, twisted,isPy37 }:
   
   buildPythonPackage rec {
     pname = "txaio";
  
positive.code:     py.test -k "not test_sdist"
    '';
  
    # Needs some fixing for 3.7
    doCheck = !isPy37;
  
    meta = with stdenv.lib; {
      description = "Utilities to support code that runs unmodified on Twisted and asyncio.";
  
negative.code:     sha256 = "67e360ac73b12c52058219bb5f8b3ed4105d2636707a36a7cdafb56fe06db7fe";
    };
  
    checkInputs = [ pytest mock ];
  
    propagatedBuildInputs = [ six twisted ];
  
  