anchor.diff:      sha256 = "294e7381dd54e73834354832604ae85567caf391c39363fed0ea2bfa86aa4304";
     };
   
  -  propagatedBuildInputs = [ six txaio twisted zope_interface cffi ] ++
  +  propagatedBuildInputs = [ six txaio twisted zope_interface cffi cryptography pynacl ] ++
       (lib.optionals (!isPy3k) [ trollius futures ]);
   
     checkInputs = [ mock pytest ];
  
positive.code:     runHook postCheck
    '';
  
    meta = with lib; {
      description = "WebSocket and WAMP in Python for Twisted and asyncio.";
      homepage    = "https://crossbar.io/autobahn";
  
negative.code: { lib, buildPythonPackage, fetchPypi, isPy3k,
    six, txaio, twisted, zope_interface, cffi, trollius, futures,
    mock, pytest, cryptography, pynacl
  }:
  buildPythonPackage rec {
    pname = "autobahn";
  