Vinay Sajip <vinay_sa...@yahoo.co.uk> added the comment:
Having looked at it again, Adrian Dries might be right that setting exc_text to None will also do the trick, and perhaps in a better way. The reasoning: Handler.format() formats record.msg % record.args, and caches it in record.message. If there is exception information, it will format that and cache it in record.exc_text, then append the exception text to the message and return that. So prepare() calling msg = self.format(record) will return the complete message and exception text in msg, and record will have record.message = record.msg % record.args, and record.exc_info and record.exc_text will have exception info. When preparing, the prepare() method pretends that the already-formatted message was logged - record.msg % record.args is equivalent to record.message with no args, so it does record.msg = msg (contains formatted message + exception info) record.args = None (since the args have already been used) record.exc_info = None (since the exception info has already been used) but I forgot that record.exc_text should also be zapped, as it should always reflect the contents of record.exc_info. So I think that setting record.exc_text to None is perhaps the correct thing to do here, as Adrian originally suggested. There should be a test that specifically exercises this with a QueueHandler and QueueListener - test_queue_listener needs to test for this case in case a regression reappears. The reason for converting record.msg, record.args, record.exc_info and record.exc_text to record.msg = fully formatted message, None, None and None is that the arguments and exception trace may not be pickleable, which is a consideration when using multiprocessing queues. Otherwise we could just have passed them over unchanged. Are you OK with changing the PR in line with the above, Cheryl? ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue34334> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
