{ lib
, buildPythonPackage
, fetchPypi

# build-system
, setuptools

# tests
, objgraph
, psutil
, python
, unittestCheckHook
}:

let greenlet = buildPythonPackage rec {
  pname = "greenlet";
  version = "3.0.1";
  pyproject = true;

  src = fetchPypi {
    inherit pname version;
    hash = "sha256-gWvZSIqUy6eNk+GrtYAA6CZvqcwqqczdbrBpasskAFs=";
  };

  nativeBuildInputs = [
    setuptools
  ];

  # tests in passthru, infinite recursion via objgraph/graphviz
  doCheck = false;

  nativeCheckInputs = [
    objgraph
    psutil
    unittestCheckHook
  ];

  preCheck = ''
    pushd ${placeholder "out"}/${python.sitePackages}
  '';

  unittestFlagsArray = [
    "greenlet.tests"
  ];

  postCheck = ''
    popd
  '';

  passthru.tests.pytest = greenlet.overridePythonAttrs (_: { doCheck = true; });

  meta = with lib; {
    changelog = "https://github.com/python-greenlet/greenlet/blob/${version}/CHANGES.rst";
    homepage = "https://github.com/python-greenlet/greenlet";
    description = "Module for lightweight in-process concurrent programming";
    license = with licenses; [
      psfl # src/greenlet/slp_platformselect.h & files in src/greenlet/platform/ directory
      mit
    ];
  };
};
in greenlet