anchor.diff: -{ stdenv, lib, fetchPypi, buildPythonPackage, isPy3k, isPy35, fetchpatch
  +{ stdenv
  +, lib
  +, fetchPypi
  +, buildPythonPackage
  +, isPy3k
  +, pythonOlder
  +, greenlet
  +, importlib-metadata
   , mock
   , pysqlite ? null
   , pytestCheckHook
  
positive.code:   dontUseSetuptoolsCheck = true;
  
    # disable mem-usage tests on mac, has trouble serializing pickle files
    disabledTests = lib.optionals isPy35 [ "exception_persistent_flush_py3k "]
      ++ lib.optionals stdenv.isDarwin [ "MemUsageWBackendTest" "MemUsageTest" ];
  
    meta = with lib; {
      homepage = "http://www.sqlalchemy.org/";
  
negative.code: 
  buildPythonPackage rec {
    pname = "SQLAlchemy";
    version = "1.4.15";
  
    src = fetchPypi {
      inherit pname version;
      sha256 = "1rj9h3mcxrgh5q8qvz7m39diyil27l5mldr49mgz6xfibk3h1w8g";
    };
  
    propagatedBuildInputs = [
      greenlet
    ] ++ lib.optionals (pythonOlder "3.8") [
      importlib-metadata
    ];
  
    checkInputs = [
  