{ stdenv
, buildPythonPackage
, fetchPypi
, pyparsing
, six
, pytestCheckHook
, pretend
, flit-core
}:

# We keep 20.4 because it uses setuptools instead of flit-core
# which requires Python 3 to build a universal wheel.

buildPythonPackage rec {
  pname = "packaging";
  version = "20.4";
  format = "setuptools";

  src = fetchPypi {
    inherit pname version;
    sha256 = "4357f74f47b9c12db93624a82154e9b120fa8293699949152b22065d556079f8";
  };

  propagatedBuildInputs = [ pyparsing six ];

  checkInputs = [
    pytestCheckHook
    pretend
  ];

  # Prevent circular dependency
  doCheck = false;

  meta = with stdenv.lib; {
    description = "Core utilities for Python packages";
    homepage = "https://github.com/pypa/packaging";
    license = [ licenses.bsd2 licenses.asl20 ];
    maintainers = with maintainers; [ bennofs ];
  };
}