[thread_queue] Uncaught exception not delivered when Bugsnag.notify was previously called.

[alx75]

Describe the bug

Uncaught exception from a ruby script is not notified to bugsnag when:

• thread_queue is chosen as a delivery method
• a notification has been sent manually by calling Bugsnag.notify('my error') any time before the uncaught exception was raised.

Steps to reproduce

Configure Bugsnag with delivery method to thread_queue

Run:
Bugsnag.notify('This is notified correctly')
raise 'This is not notified with thread_queue'

Environment

• Bugsnag version: 6.24.0
• Ruby version: 2.7.6
• Bundle version: 2.3.4
• Rails version: 6.1.6.1

My understanding of the issue

Bugsnag::Delivery::ThreadQueue registers a at_exit to finish processing all notifications from the queue and then stop the thread that dequeue the notifications.
Bugsnag register a at_exit hook to deliver the unhandled error to Bugsnag::Delivery::ThreadQueue

This doesn't work when a notification was first sent with Bugsnag.notify because afterward, raising an unhandled error will be processed by Bugsnag at_exit however Bugsnag::Delivery::ThreadQueue at_exit was already processed.

[hamudi-ahmed]

Hi @alx75 , thanks for reporting this. I've been able to reproduce the issue - we're going to take a look as soon as priorities allow.

[alx75]

Ok thanks. Easy workaround is to use synchronous delivery mode for scripts.

[johnkiely1]

Hi @alx75 . Just a quick update, this does seem to be an issue for Ruby scripts that aren't running in a webserver.
We're looking to fix it in the next major version release, for now using the synchronous delivery looks like a good option as a workaround. We will update again once that has been released.