'If the child process run by ``_sync_command_error_squashed`` exits with
an an error status then the function nevertheless returns ``None``.'

@validateLogging(error_status_logged)
def test_error_exit(self, logger):

    result = _sync_command_error_squashed(['python', '-c', 'raise    SystemExit(1)'], logger)
    self.assertIs(None, result)
