Argparse expects exit() to be a terminal function and not return.
        As such, this function must raise an exception instead.

def exit(self, status=0, message=None):
        '''
        Argparse expects exit() to be a terminal function and not return.
        As such, this function must raise an exception instead.
        '''
        self.exited = True
        self.status = status

        if message is not None:
            self.outp.printf(message)
        raise s_exc.ParserExit(mesg=message, status=status)