Running tests/integration/test_distributed_processing/test_multithreaded_vs_singlethreaded fails on my laptop because celery/RabbitMQ is running very slowly. There seems to be some hang up when the celery head node communicates with subprocesses that causes significant slowdown. In particular, I've found that the birth cycle gets hung up in communication between mauscelery.mausworker.sub_process_broadcast and mauscelery.mausprocess.process_birth but it looks like individual spill processing is also proceeding slowly.

I checked for this in control room branch in MLCR and things look okay - so it could be a feature of my laptop or the release branch.