Fix test failure in OSX with OpenMP called from multiple threads

[mdouze]

Need to add an ssh key to the circleci to be able to debug

For my own ref, how to connect to the job:

[matthijs@matthijs-mbp /Users/matthijs/Desktop/faiss_github/circleci_keys] ssh -p 54782 38.39.188.110 -i id_ed25519

[mdouze]

I can repro:

bash-3.2$ PYTHONPATH=../build/faiss/python/build/lib/ python3 -m unittest test_index_binary
..nb tests 20 44
..WARNING clustering 200 points to 8 centroids: please provide at least 312 training points
..WARNING clustering 200 points to 10 centroids: please provide at least 390 training points
[7 7 8 8 8] [7 7 8 8 8]
[812 866 121 452 578] [812 866 452 578 121]
...WARNING clustering 256 points to 32 centroids: please provide at least 1248 training points
...OMP: Error #131: Thread identifier invalid.
Abort trap: 6
bash-3.2$ pwd
/Users/distiller/project/tests

[mdouze]

More accurate:

bash-3.2$ PYTHONPATH=../build/faiss/python/build/lib/ python3 -m unittest test_index_binary.TestReplicasAndShards.test_replicas
OMP: Error #13: Assertion failure at kmp_runtime.cpp(3689).
OMP: Hint Please submit a bug report with this message, compile and run commands used, and machine configuration info including native compiler and operating system versions. Faster response will be obtained by including all program sources. For information on submitting this issue, please see https://bugs.llvm.org/.
Abort trap: 6

[mdouze]

lldb backtrace:
https://gist.github.com/mdouze/d4f3bf7e2edec4ff207d4c869eacfd0c

Could be because an OMP parallel loop is called from several threads.

[mdouze]

Works when setting nb threads to 1: https://gist.github.com/mdouze/3af918414f8cf6e90d996e0f3306008d

[mdouze]

Same story with test_meta_index:

https://gist.github.com/mdouze/4e1f6573e9438583b7677a78f5c89f46

[mdouze]

Hmm now homebrew is down on OSX. I guess I'll have to wait.

[facebook-github-bot]

@mdouze has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[facebook-github-bot]

@mdouze merged this pull request in 4dc5b27.