Fatal Python error: Segmentation fault with Python Free Threading (nogil)

[dan-glass]

Python3.13t Free Threading / nogil:

Fatal Python error: Segmentation fault

Current thread 0x00007f7a40c70740 (most recent call first):
  File "/usr/local/lib/python3.13t/dist-packages/viztracer/tracer.py", line 261 in stop
  File "/usr/local/lib/python3.13t/dist-packages/viztracer/viztracer.py", line 189 in stop
...
  File "/usr/lib/python3.13/threading.py", line 363 in wait
  File "/usr/lib/python3.13/threading.py", line 659 in wait

Extension modules: viztracer.snaptrace, viztracer.vcompressor (total: 2)

Can reproduce every time, but not with debug version of Python, nor with valgrind. Unfortunately I have not had time to create a small repro to share.

[gaogaotiantian]

Thank you for the report. I wouldn't be surprised if viztracer fails on 3.13t - we do not have a test environment set up for it. I built the 3.13t wheels because it could be useful for some experimenters. Even 3.13t itself is not officially supported - it has plenty of issues itself. That being said, I can take a look at the issue if there's a repro, but there's not a lot that I can do without any code. Hopefully github actions can support 3.13t so I can at least run my test suites with it.

[dan-glass]

I hit a similar issue with Yappi and developed a simple repro here: sumerc/yappi#179

[gaogaotiantian]

I'm not able to repro the issue with the example given.

[dan-glass]

That repro was for yappi, I hadn't tested on viztracer, but thank you. I was able to work around the issue by completely shutting down all the threads in the process before calling stop().