Remote object type error

[WqyJh]

I'm using apscheduler with rpyc, the service expose two of scheduler's method.
remove_job works perfectly but add_job crashed.

class SchedulerService(rpyc.Service):
    def exposed_add_job(self, *args, **kwargs):
        return self.scheduler.add_job(*args, **kwargs)

    def exposed_remove_job(self, job_id, jobstore=None):
        return self.scheduler.remove_job(job_id, jobstore=jobstore)

My local call is as follows:

        scheduler.remove_job(job_id)

        _trigger = CronTrigger.from_crontab(mirror.sync_time)
        scheduler.add_job(sync_mirror, trigger=_trigger,
                          id=job_id,
                          args=(mirror,))

This is the remote traceback: the _create_trigger method in the apscheduler failed.

========= Remote Traceback (1) =========
Traceback (most recent call last):
  File "/home/linux/venv/mirrorit-qbPURi0Y/lib/python3.6/site-packages/rpyc/core/protocol.py", line 323, in _dispatch_request
    res = self._HANDLERS[handler](self, *args)
  File "/home/linux/venv/mirrorit-qbPURi0Y/lib/python3.6/site-packages/rpyc/core/protocol.py", line 585, in _handle_call
    return obj(*args, **dict(kwargs))
  File "/home/linux/Works/PyCharmProjects/mirrorit/mirrorit/scheduler.py", line 42, in exposed_add_job
    return self.scheduler.add_job(*args, **kwargs)
  File "/home/linux/venv/mirrorit-qbPURi0Y/lib/python3.6/site-packages/apscheduler/schedulers/base.py", line 420, in add_job
    'trigger': self._create_trigger(trigger, trigger_args),
  File "/home/linux/venv/mirrorit-qbPURi0Y/lib/python3.6/site-packages/apscheduler/schedulers/base.py", line 915, in _create_trigger
    trigger.__class__.__name__)
TypeError: Expected a trigger instance or string, got ABCMeta instead

As we can see from the source code of _create_trigger, it determines whether the trigger is an instance of BaseTrigger. The _trigger variable created by CronTrigger.from_crontab(mirror.sync_time) is an instance of class CronTrigger(BaseTrigger), therefore it's indeed an instance of BaseTrigger. However, the server end resolved this argument to an instance of ABCMeta which cause the exception. Actually, BaseTrigger is a subclass of ABCMeta (class BaseTrigger(six.with_metaclass(ABCMeta))).

    def _create_trigger(self, trigger, trigger_args):
        if isinstance(trigger, BaseTrigger):
            return trigger
        elif trigger is None:
            trigger = 'date'
        elif not isinstance(trigger, six.string_types):
            raise TypeError('Expected a trigger instance or string, got %s instead' %
                            trigger.__class__.__name__)

        # Use the scheduler's time zone if nothing else is specified
        trigger_args.setdefault('timezone', self.timezone)

        # Instantiate the trigger class
        return self._create_plugin_instance('trigger', trigger, trigger_args)

Therefore, I think the remote object type should be the base class type rather than the top level super class type.

Environment

• rpyc version: 4.1.2
• python version: 3.6.5
• operating system: Deepin 15.11