3930: Garbage collection and registered signals cause errors during cron job execution of index and session cleanup tasks

gja****@clearpathr*********** (Google Code) (Is this you? Claim this profile.)
What version are you running?
2.5 beta2

What's the URL of the page containing the problem?

CRON tasks as defined in conf/cron.conf

What steps will reproduce the problem?

1.Use the provided cron jobs via crontab as per https://www.reviewboard.org/docs/manual/2.5/admin/sites/search-indexing/
2. Execute cron task
3. Observe STDERR output

What is the expected output? What do you see instead?

Task completes, but generates STDERR output which shows an error:

Exception TypeError: TypeError('isinstance() arg 2 must be a class, type, or tuple of classes and types',) in <bound method Signal._remove_receiver of <django.dispatch.dispatcher.Signal object at 0x7f9b106be750>> ignored

Assuming if root issue can't be resolved, this exception should be trapped and logged so as to not create misleading CRON task reports / errors?

What operating system are you using? What browser?

Ubuntu Server 14.04 / Google Chrome (not applicable)

Please provide any additional information below.

See existing forum thread at: