TL;DR summary: interesting... in my case reliably fails locally on python 3.6 and 3.7 but not 2.7 even with fresh release of 0.13.0 reported upstream https://github.com/joblib/joblib/issues/870
Thanks for the patch -- I will xfail it in 0.13.0-1 with this, upload to unstable, and then upload 0.13.2-1 with it to experimental Some notes collected: 1. I think it is the same issue as https://github.com/joblib/joblib/issues/758 which was addressed upstream in commit f58e833df6802bbc2120a9eb2c608a8c35dbc099 Author: Olivier Grisel <olivier.gri...@ensta.org> Date: Mon Aug 27 11:34:30 2018 +0200 Fix a bug in nesting level computation with FallbackToBackend(SequentialBackend()) (#759) which is $> git describe --contains f58e833df6802bbc2120a9eb2c608a8c35dbc099 0.12.3~5 so might have been regression in Version: 0.13.0-1 where (on upstream) taskset -c 0 python -m pytest -v -k test_nested_parallelism_limit passes just ok, so probably not a straight regression. 2. Could trigger "reliably" for the second (python 3.7) test run while passing for 2.7 with change $> git diff diff --git a/debian/rules b/debian/rules index 0ede50a..dd4d8ef 100755 --- a/debian/rules +++ b/debian/rules @@ -22,7 +22,7 @@ override_dh_auto_test: ${PYVERS:%=python-test%} ${PY3VERS:%=python-test%} python-test%: ifeq (,$(filter nocheck,$(DEB_BUILD_OPTIONS))) - PYTHONPATH=$(CURDIR) python$* /usr/bin/py.test -s -v joblib; + PYTHONPATH=$(CURDIR) python$* /usr/bin/py.test -s -v -k test_nested_parallelism_limit joblib; else : # Skip unittests due to nocheck endif and running taskset -c 0 fakeroot debian/rules binary > Note: I've checked and this failure may be reproduced easily on any > system by doing "taskset -c 0 dpkg-buildpackage", but if for whatever > reason you need a single-CPU system to test, please contact me > privately and I will gladly provide one. > Thanks. > --- a/joblib/test/test_parallel.py > +++ b/joblib/test/test_parallel.py > @@ -1429,6 +1429,7 @@ def _recursive_backend_info(limit=3, **kwargs): > return this_level + results[0] > +@pytest.mark.xfail > @with_multiprocessing > @parametrize('backend', ['loky', 'threading']) > def test_nested_parallelism_limit(backend): Cheers, -- Yaroslav O. Halchenko Center for Open Neuroscience http://centerforopenneuroscience.org Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755 Phone: +1 (603) 646-9834 Fax: +1 (603) 646-1419 WWW: http://www.linkedin.com/in/yarik