#120868 was caused by an eager construction of multiprocessing.Manager used to check if the queue passed in to the logging config was an instance of multiprocessing.Manager.Queue / multiprocessing.Manager.JoinableQueue. This could cause unexpected exceptions in environments where a multiprocessing.Manager couldn't be created.

The proposed fix moves the check for these classes, and creation of multiprocessing.Manager which is necessary for this, to a point where we've ruled out all other valid options for queue, and are certain that multiprocessing.Manager has been used to produce the object passed via queue.

• Issue: 3.12.4 breakslogging.config.DictConfig with logging.handlers.QueueHandler on read-only file systems #120868