anchor.diff:  , buildPythonPackage
   , fetchPypi
   , setuptools_scm
  -, pytest
  +, pytestCheckHook
   , pytest-flake8
   , glibcLocales
   , packaging
   , isPy27
  +, isPy38
   , backports_os
   , importlib-metadata
   , fetchpatch
  
positive.code:     license = lib.licenses.mit;
    };
  
    checkPhase = ''
      # ignore performance test which may fail when the system is under load
      py.test -v -k 'not TestPerformance'
    '';
  
    patches = [
      (fetchpatch {
  
negative.code:     sha256 = "9f2169633403aa0423f6ec000e8701dd1819526c62465f5043952f92527fea0f";
    };
  
    checkInputs = [ pytestCheckHook pytest-flake8 glibcLocales packaging ];
    buildInputs = [ setuptools_scm ];
    propagatedBuildInputs = [
      importlib-metadata
  