image classifier feature extractor segfault on Linux

[guihao-liang]

toolkits/test_image_classifier.py::ImageClassifierSqueezeNetTest::test_predict_topk Fatal Python error: Segmentation fault

...

Thread 0x00007f4d91ffb700 (most recent call first):
  File "/usr/lib/python3.6/threading.py", line 295 in wait
  File "/usr/lib/python3.6/queue.py", line 164 in get
  File "/usr/lib/python3.6/multiprocessing/pool.py", line 108 in worker
  File "/usr/lib/python3.6/threading.py", line 864 in run
  File "/usr/lib/python3.6/threading.py", line 916 in _bootstrap_inner
  File "/usr/lib/python3.6/threading.py", line 884 in _bootstrap

Thread 0x00007f4e88519740 (most recent call first):
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/turicreate/extensions.py", line 165 in _run_toolkit_function
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/turicreate/extensions.py", line 181 in <lambda>
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/turicreate/toolkits/_image_feature_extractor.py", line 139 in next_batch
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/turicreate/toolkits/_image_feature_extractor.py", line 179 in extract_features
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/turicreate/toolkits/image_classifier/image_classifier.py", line 841 in _extract_features
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/turicreate/toolkits/image_classifier/image_classifier.py", line 637 in predict_topk
  File "/build/scenario-tests/tests/toolkits/test_image_classifier.py", line 211 in test_predict_topk
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/python.py", line 184 in pytest_pyfunc_call
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/unittest.py", line 220 in wrapped_testMethod
  File "/usr/lib/python3.6/unittest/case.py", line 605 in run
  File "/usr/lib/python3.6/unittest/case.py", line 653 in __call__
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/unittest.py", line 232 in runtest
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/runner.py", line 135 in pytest_runtest_call
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/runner.py", line 217 in <lambda>
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/runner.py", line 244 in from_call
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/runner.py", line 217 in call_runtest_hook
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/runner.py", line 186 in call_and_report
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/runner.py", line 100 in runtestprotocol
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/runner.py", line 85 in pytest_runtest_protocol
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/main.py", line 272 in pytest_runtestloop
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/main.py", line 247 in _main
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/main.py", line 191 in wrap_session
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/main.py", line 240 in pytest_cmdline_main
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/callers.py", line 187 in _multicall
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 87 in <lambda>
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/manager.py", line 93 in _hookexec
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/pluggy/hooks.py", line 286 in __call__
  File "/build/scenario-tests/venv/lib/python3.6/site-packages/_pytest/config/__init__.py", line 125 in main
  File "/build/scenario-tests/venv/bin/pytest", line 8 in <module>
Segmentation fault (core dumped)

[guihao-liang]

The initial guess is the last batch returned by next_batch is not filled in batch size.

[TobyRoseman]

Is this the same issue as #3079?

[guihao-liang]

Is this the same issue as #3079?

right. I thought it's fixed, but it happened again.

[TobyRoseman]

The issue only happens intermittently. Nothing with the image classifier has changed in a long time. I would guess it’s more likely to be an issue with the machine than with our code.

[TobyRoseman]

The stack trace seems to be the same as #3044. Closing as a duplicate.