celery 'Worker-n' pid:xxxx exited with 'exitcode 1' when I import hmmlearn

Question

In my tasks.py file, when I import hmmlearn,

from hmmlearn import hmm

and start my celery workers, I get the following error

Answer 1

This might be because celery 3.1.xx comes bundled with billiard 3.3.

If you upgrade that package (to 3.5 at time of writing), the service might work again.

pip install --upgrade billiard