anchor.diff:    src = fetchPypi {
       pname = "glean_parser";
       inherit version;
  -    hash = "sha256-PjOMNUnrz0kDfYEXv5Ni/9RIHn4Yylle6NJOK1Rb3SY=";
  +    hash = "sha256-vEGleqQytNYyy/DfHwqxrHIOMCj4sZTavfuxyDc5O30=";
     };
   
     postPatch = ''
       substituteInPlace setup.py \
         --replace "pytest-runner" "" \
  -      --replace "MarkupSafe==2.0.1" "MarkupSafe"
  +      --replace "MarkupSafe>=1.1.1,<=2.0.1" "MarkupSafe>=1.1.1"
     '';
   
     nativeBuildInputs = [
  
positive.code:     pytestCheckHook
    ];
  
    disabledTests = [
      # https://bugzilla.mozilla.org/show_bug.cgi?id=1741668
      "test_validate_ping"
    ];
  
    pythonImportsCheck = [
  
negative.code: 
  buildPythonPackage rec {
    pname = "glean-parser";
    version = "6.1.1";
    format = "setuptools";
  
    disabled = pythonOlder "3.6";
  