UnboundLocalError encounter in _WorkerThread

[TariqAHassan]

Issues

An UnboundLocalError can be encountered in _WorkerThread.

Checklist

What OS are you using?

Ubuntu 18.04

What version of Dramatiq are you using?

v1.10.0

What did you do?

Worker thread attempted to process a message.

What did you expect would happen?

Actor to be defined.

What happened?

It's possible for an UnboundLocalError to be encountered in dramatiq/worker.py in the _WorkerThread.process_message() method. The relevant piece of code is:

        try:
            self.logger.debug("Received message %s with id %r.", message, message.message_id)
            self.broker.emit_before("process_message", message)

            res = None
            if not message.failed:
                actor = self.broker.get_actor(message.actor_name)
            ...

        except SkipMessage:
            self.logger.warning("Message %s was skipped.", message)
            self.broker.emit_after("skip_message", message)

        except BaseException as e:
            ...
            throws = message.options.get("throws") or actor.options.get("throws")
...

That is, if actor = self.broker.get_actor(message.actor_name) does not run, actor will not be defined below.

[Bogdanp]

Interesting! Do you know what the original error was?

[TariqAHassan]

Hey Bogdanp.

Thanks for the fast reply.

I do not, unfortunately. However, an exception in self.broker.emit_before() could precipitate this problem.

[ashleybartlett]

@Bogdanp any chance of getting this in a release soon?

[Bogdanp]

@ashleybartlett I just released 1.11.

[ashleybartlett]

Thank you @Bogdanp !