[BUG-REPORT] vaex causes a segmentation fault on windows

[iisakkirotko]

Description
We're seeing a Windows fatal exception: access violation running vaex-core 4.18.1 on windows with Python 3.9, not sure if the issue also affects other Python versions. I mentioned this in #2439 (comment), believing it to be related, but this issue persists with vaex-core 4.18.1, as can be see in this CI run.

Software information

• Vaex version (import vaex; vaex.__version__): vaex-core 4.18.1
• Vaex was installed via: pip
• OS: Microsoft Windows Server 2022 10.0.20348 from github runners windows-latest.

Additional information
The full stack trace is

Stack Trace

Thread 0x00001d58 (most recent call first):
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\hash.py", line 171 in add
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\cpu.py", line 344 in process
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\execution.py", line 564 in process_tasks
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\execution.py", line 500 in process_part
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\multithreading.py", line 80 in wrapped
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\concurrent\futures\thread.py", line 58 in run
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\concurrent\futures\thread.py", line 83 in _worker
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 917 in run
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 980 in _bootstrap_inner
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 937 in _bootstrap
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\solara\server\patch.py", line 306 in _WidgetContextAwareThread__bootstrap
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\solara\server\patch.py", line 284 in WidgetContextAwareThread__bootstrap

Current thread 0x00001cf4 (most recent call first):
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\hash.py", line 171 in add
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\cpu.py", line 3[44](https://github.com/widgetti/solara/actions/runs/11249248897/job/31275859331#step:9:45) in process
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\execution.py", line 564 in process_tasks
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\execution.py", line 500 in process_part
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\vaex\multithreading.py", line 80 in wrapped
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\concurrent\futures\thread.py", line 58 in run
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\concurrent\futures\thread.py", line 83 in _worker
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 917 in run
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 980 in _bootstrap_inner
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 937 in _bootstrap
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\solara\server\patch.py", line 306 in _WidgetContextAwareThread__bootstrapWindows fatal exception: 
access violation

  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\solara\server\patch.py", line 284 in WidgetContextAwareThread__bootstrap

Thread 0x000019ec (most recent call first):
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 316 in wait
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 581 in wait
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 1304 in run
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 980 in _bootstrap_inner
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 937 in _bootstrap
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\solara\server\patch.py", line 306 in _WidgetContextAwareThread__bootstrap
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\site-packages\solara\server\patch.py", line 284 in WidgetContextAwareThread__bootstrap

Thread 0x000019fc (most recent call first):
  File "C:\hostedtoolcache\windows\Python\3.9.13\x64\lib\threading.py", line 312 in waitD:\a\_temp\73d90dee-0906-4bd0-95c2-c4[46](https://github.com/widgetti/solara/actions/runs/11249248897/job/31275859331#step:9:47)22c2060b.sh: line 3:   311 Segmentation fault      pytest tests/unit --doctest-modules --timeout=60

[ddelange]

potentially a memory leak specific to windows:

https://stackoverflow.com/questions/64421004/how-to-debug-access-violation-memory-issues-in-python-under-windows#comment113941849_64421004

[maartenbreddels]

I wonder if we should use the same wheel we build for releasing in the testing.

[ddelange]

cibuildwheel has built-in support to run pytest on built wheels right after building them https://cibuildwheel.pypa.io/en/stable/options/#testing

[setu4993]

@maartenbreddels @ddelange : Sorry to bother you but curious when a fix with this might roll out? Maybe a version that skips Windows temporarily might be easier?

[setu4993]

Bump... Any idea when this might be resolved? It has been >a month since the last version was yanked.

Maybe it makes sense to release without Windows support in the meanwhile?

[ddelange]

from my side it's not clear what would be the fix

[setu4993]

@maartenbreddels : Anything you can do to help here? Maybe release for other OSes except Windows?

It's getting really hard to keep using vaex because the narrow slices of versions that work with the rest of the ecosystem. This is blocking Python 3.11+, NumPy 2.0, etc. updates.

[ddelange]

I would also vote to release vaex-core (with or without including the windows wheels, since vaex CI isn't reproducing this error anyway) and all other vaex packages that #2331 touched.

numpy v2 is a separate issue (not worked on, not fixed yet on master): #2425 (comment)