def test_error_custom_dns(program, error_code, expected_message):
exc = ConnectionError('Connection aborted')
exc.__context__ = socket.gaierror(error_code, "<test>")
program.side_effect = exc
r = http('www.google.com', tolerate_error_exit_status=True)
assert r.exit_status == ExitStatus.ERROR
assert expected_message in r.stderr
