anchor.diff:  
     checkInputs = [
       netcdf4
  -  ] ++ lib.optional (pythonOlder "3.3") mock;
  +  ];
   
  -  doCheck = true;
     checkPhase = ''
       runHook preCheck
       cd ./test/ci_tests
  
positive.code: {lib, fetchFromGitHub, pythonOlder, buildPythonPackage, gfortran, mock, xarray, wrapt, numpy, netcdf4, setuptools}:
  
  buildPythonPackage rec {
    pname = "wrf-python";
    version = "1.3.3";
  
    src = fetchFromGitHub {
      owner = "NCAR";
      repo = "wrf-python";
      rev = version;
      sha256 = "sha256-+v4FEK0FVE0oAIb18XDTOInHKfxXyykb1ngk9Uxwf0c=";
    };
  
    propagatedBuildInputs = [
  
negative.code:     runHook postCheck
    '';
  
    pythonImportsCheck = [
      "wrf"
    ];
  
    meta = with lib; {
      description = "WRF postprocessing library for Python";
      homepage = "http://wrf-python.rtfd.org";
      license = licenses.asl20;
      maintainers = with maintainers; [ mhaselsteiner ];
    };
  }
  