Haven't done research but bandersnatch's (https://github.com/pypa/bandersnatch) Unit tests pass in 3.7 and cause Python to Segmentation Fault in Python 3.8.0b4+.

```
py38 run-test: commands[0] | coverage run -m pytest
============================= test session starts ==============================
platform linux -- Python 3.8.0b4+, pytest-5.1.2, py-1.8.0, pluggy-0.13.0
cachedir: .tox/py38/.pytest_cache
rootdir: /home/travis/build/pypa/bandersnatch, inifile: pytest.ini
plugins: timeout-1.3.3
Fatal Python error: Segmentation fault
```

Full failure on Travis CI: https://travis-ci.org/pypa/bandersnatch/jobs/584973434

Seems to be with coverage actually.

```
ERROR: InvocationError for command /home/travis/build/pypa/bandersnatch/.tox/py38/bin/coverage run -m pytest (exited with code -11)
```

Adding in Nightly Passed: https://travis-ci.org/pypa/bandersnatch/jobs/584977510

Current 3.8 beta still failing: https://travis-ci.org/pypa/bandersnatch/builds/584977503

So please just close if the bug was known etc. and I'll just live with the failing test until the next 3.8 comes out.

If you mean that the crash no longer occurs with current 3.8.b4+ in the repository, then you should close as 'out-of-date.

Happy to close, just was not 100% sure if the fix is merged into the 3.8 branch. I mainly opened this bug to ensure that has been done.

Victor, am I correct in thinking that this should be closed as either intermittent, lacking in sufficient information for us to do anything, or possibly a 3rd party issue?

The Travis CI job contains the Python traceback where the bug occurs.

It seems like the crash occurs at multidict/__init__.py:23 which imports multidict._multidict which is a C extension.

> Full failure on Travis CI: https://travis-ci.org/pypa/bandersnatch/jobs/584973434

$ pip --version

pip 19.2.3 from /home/travis/virtualenv/python3.8-dev/lib/python3.8/site-packages/pip (python 3.8)
install.1

1.02s$ pip install --upgrade pip setuptools
install.2

4.44s$ pip install -r requirements.txt -r requirements_test.txt
install.3

1.48s$ pip install .

12.98s$ python test_runner.py

GLOB sdist-make: /home/travis/build/pypa/bandersnatch/setup.py

py38 create: /home/travis/build/pypa/bandersnatch/.tox/py38

py38 installdeps: -rrequirements_test.txt

py38 inst: /home/travis/build/pypa/bandersnatch/.tox/.tmp/package/1/bandersnatch-3.4.1.zip

py38 installed: aiohttp==3.6.0,apipkg==1.5,appdirs==1.4.3,async-timeout==3.0.1,atomicwrites==1.3.0,attrs==19.1.0,bandersnatch==3.4.1,black==19.3b0,certifi==2019.9.11,chardet==3.0.4,Click==7.0,codecov==2.0.15,coverage==4.5.4,execnet==1.7.1,filelock==3.0.12,freezegun==0.3.12,idna==2.8,more-itertools==7.2.0,multidict==4.5.2,packaging==19.1,pluggy==0.13.0,py==1.8.0,pyparsing==2.4.2,pytest==5.1.2,pytest-cache==1.0,pytest-timeout==1.3.3,python-dateutil==2.8.0,requests==2.22.0,six==1.12.0,toml==0.10.0,tox==3.14.0,urllib3==1.25.3,virtualenv==16.7.5,wcwidth==0.1.7,xmlrpc2==0.3.1,yarl==1.3.0

py38 run-test-pre: PYTHONHASHSEED='690490585'

py38 run-test: commands[0] | coverage run -m pytest

============================= test session starts ==============================

platform linux -- Python 3.8.0b4+, pytest-5.1.2, py-1.8.0, pluggy-0.13.0

cachedir: .tox/py38/.pytest_cache

rootdir: /home/travis/build/pypa/bandersnatch, inifile: pytest.ini

plugins: timeout-1.3.3

Fatal Python error: Segmentation fault

Current thread 0x00007fabb284a700 (most recent call first):

  File "<frozen importlib._bootstrap>", line 219 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 1109 in exec_module

  File "<frozen importlib._bootstrap>", line 671 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 975 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 991 in _find_and_load

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/multidict/__init__.py", line 23 in <module>

  File "<frozen importlib._bootstrap>", line 219 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 783 in exec_module

  File "<frozen importlib._bootstrap>", line 671 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 975 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 991 in _find_and_load

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/aiohttp/hdrs.py", line 6 in <module>

  File "<frozen importlib._bootstrap>", line 219 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 783 in exec_module

  File "<frozen importlib._bootstrap>", line 671 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 975 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 991 in _find_and_load

  File "<frozen importlib._bootstrap>", line 219 in _call_with_frames_removed

  File "<frozen importlib._bootstrap>", line 1042 in _handle_fromlist

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/aiohttp/__init__.py", line 5 in <module>

  File "<frozen importlib._bootstrap>", line 219 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 783 in exec_module

  File "<frozen importlib._bootstrap>", line 671 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 975 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 991 in _find_and_load

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/bandersnatch/verify.py", line 14 in <module>

  File "<frozen importlib._bootstrap>", line 219 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 783 in exec_module

  File "<frozen importlib._bootstrap>", line 671 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 975 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 991 in _find_and_load

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/bandersnatch/main.py", line 17 in <module>

  File "<frozen importlib._bootstrap>", line 219 in _call_with_frames_removed

  File "<frozen importlib._bootstrap_external>", line 783 in exec_module

  File "<frozen importlib._bootstrap>", line 671 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 975 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 991 in _find_and_load

  File "/home/travis/build/pypa/bandersnatch/src/bandersnatch/tests/test_main.py", line 10 in <module>

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/assertion/rewrite.py", line 140 in exec_module

  File "<frozen importlib._bootstrap>", line 671 in _load_unlocked

  File "<frozen importlib._bootstrap>", line 975 in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 991 in _find_and_load

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/py/_path/local.py", line 701 in pyimport

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/python.py", line 501 in _importtestmodule

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/python.py", line 433 in _getobj

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/python.py", line 256 in obj

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/python.py", line 449 in _inject_setup_module_fixture

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/python.py", line 436 in collect

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/runner.py", line 247 in <lambda>

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/runner.py", line 220 in from_call

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/runner.py", line 247 in pytest_make_collect_report

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/callers.py", line 187 in _multicall

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/manager.py", line 83 in <lambda>

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/manager.py", line 92 in _hookexec

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/hooks.py", line 286 in __call__

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/runner.py", line 363 in collect_one_node

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/main.py", line 701 in genitems

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/main.py", line 476 in _perform_collect

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/main.py", line 437 in perform_collect

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/main.py", line 244 in pytest_collection

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/callers.py", line 187 in _multicall

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/manager.py", line 83 in <lambda>

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/manager.py", line 92 in _hookexec

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/hooks.py", line 286 in __call__

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/main.py", line 234 in _main

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/main.py", line 191 in wrap_session

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/main.py", line 228 in pytest_cmdline_main

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/callers.py", line 187 in _multicall

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/manager.py", line 83 in <lambda>

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/manager.py", line 92 in _hookexec

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pluggy/hooks.py", line 286 in __call__

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/_pytest/config/__init__.py", line 78 in main

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/pytest.py", line 101 in <module>

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/coverage/execfile.py", line 192 in run_python_file

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/coverage/execfile.py", line 122 in run_python_module

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/coverage/cmdline.py", line 627 in do_run

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/coverage/cmdline.py", line 491 in command_line

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/lib/python3.8/site-packages/coverage/cmdline.py", line 756 in main

  File "/home/travis/build/pypa/bandersnatch/.tox/py38/bin/coverage", line 10 in <module>

ERROR: InvocationError for command /home/travis/build/pypa/bandersnatch/.tox/py38/bin/coverage run -m pytest (exited with code -11)

> Victor, am I correct in thinking that this should be closed as either intermittent, lacking in sufficient information for us to do anything, or possibly a 3rd party issue?

It can be a Python 3.8 or a bug in third party code. I suggest to attempt to reproduce the bug in gdb to collect more info about this crash.

I am not sure about the difference between python 3.8-dev and nightly . The pipelines seem to have same configuration. The version on both pipelines is 3.8.0b4+ and the nightly build passes : https://travis-ci.org/pypa/bandersnatch/jobs/588664064 . Maybe getting the exact commit hash for the python version might help here in trying to replicate the issue under the environment.

I suggest to wait one or two weeks, and if the bug doesn't reoccur: simply close the issue.

https://docs.travis-ci.com/user/languages/python/ make no mention of the difference between "3.8-dev" and "nightly". I'd expect it to be latest released 3.8 alpha/beta and Trunk (or possibly trunk on 3.8 branch) respectively.

Have reached out via Twitter (unable to see a contact anywhere on their website) to see if we can get clarity: https://twitter.com/cooperlees/status/1176485344553754624

It seems now bandersnatch is tested with python 3.8.0 stable release and passes : https://travis-ci.org/pypa/bandersnatch/builds/599806554 . @cooperlees, can you please confirm and close the issue?

I will do it differently. Nobody managed to reproduce the bug. The upstream CI looks to be fine. So I close the issue.

If someone sees a crash, please open a new issue with more context, like explain how to reproduce it ;-)