{ lib, buildPythonPackage, fetchPypi, pythonOlder, isPy3k, python, typing }: let testDir = if isPy3k then "src_py3" else "src_py2"; in buildPythonPackage rec { pname = "typing_extensions"; version = "3.7.4.2"; src = fetchPypi { inherit pname version; sha256 = "79ee589a3caca649a9bfd2a8de4709837400dfa00b6cc81962a1e6a1815969ae"; }; checkInputs = lib.optional (pythonOlder "3.5") typing; # Error for Python3.6: ImportError: cannot import name 'ann_module' # See https://github.com/python/typing/pull/280 doCheck = pythonOlder "3.6"; checkPhase = '' cd ${testDir} ${python.interpreter} -m unittest discover ''; meta = with lib; { description = "Backported and Experimental Type Hints for Python 3.5+"; homepage = "https://github.com/python/typing"; license = licenses.psfl; maintainers = with maintainers; [ pmiddend ]; }; }