Flaky test for hybrid.Log to shared queue

[randomir]

Example here. But happens on windows as well.

test_shared_memo_queue sometimes fails for memo=multiprocessing.Queue().

Multiprocessing queue probably needs some time for eventual consistency (and we are not giving any).

[randomir]

Reason: see note under Pipes and Queues section:

When an object is put on a queue, the object is pickled and a background thread later flushes the pickled data to an underlying pipe.
[...]
After putting an object on an empty queue there may be an infinitesimal delay before the queue’s empty() method returns False and get_nowait() can return without raising queue.Empty.