anchor.diff:      msgpack
     ];
   
  +  checkInputs = [ pytest ];
  +  # add testsupport.py to PATH
  +  # ignore network related tests, which fail in sandbox
     checkPhase = ''
  -    ${python.interpreter} setup.py test
  +    PYTHONPATH=tests/PyroTests:$PYTHONPATH
  +    pytest -k 'not StartNSfunc \
  +               and not Broadcast \
  +               and not GetIP' \
  +           --ignore=tests/PyroTests/test_naming.py
     '';
   
     meta = with stdenv.lib; {
  
positive.code: , cloudpickle
  , msgpack
  , isPy27
  , isPy33
  , selectors34
  }:
  
  buildPythonPackage rec {
  
negative.code: 
    propagatedBuildInputs = [
      serpent
    ] ++ lib.optionals isPy27 [ selectors34 ];
  
    buildInputs = [
      dill
  