ask/celery — pull request #705 by mthurman (2012-06-01 00:26:53+00:00)
Title: Loggers expect exc_info to be falsey or a tuple, pass in the tuple

I'm actually not sure how useful sending exc_info is at all. It may also be desirable to have some flag here so that exc_info can be omitted when it's a RetryTaskError called from on_failure. IMO, logging those tracebacks probably isn't that helpful.