Bug 941160 – sys-apps/portage+dev-lang/python:3.13[jit]: emerge freezes

• Status: UNCONFIRMED
• Product: Portage Development

[Description Aliaksei Urbanski 2024-10-08 12:09:45 UTC]

Hello everyone,

I've found that when I try to run emerge using Python 3.13 that is built with experimental JIT, emerge gets stuck while calculating dependencies.

I suppose this may be a quite painful issue for those who tried to migrate to Python 3.13 with JIT and for some reason disabled previous Python versions support for portage.

Best regards!

Reproducible: Always

Steps to Reproduce:
1. USE="jit python_targets_python3_13" emerge dev-lang/python:3.13 sys-apps/portage -1av
2. Add/move python3.13 to the top of the list at /etc/python-exec/python-exec.conf
3. emerge world -DNuav
Actual Results:  
emerge freezes when calculating dependencies

Expected Results:  
emerge calculates dependencies and shows the results

[Comment 1 Aliaksei Urbanski 2024-10-08 12:14:19 UTC]

Created attachment 905107 [details]
emerge sys-apps/portage dev-lang/python:3.13 --info

[Comment 2 Sam James 2024-10-08 12:21:39 UTC]

I've not yet played with the JIT at all, so limited ideas to start with.

If you attach gdb & pdb, can you get both backtraces?

[Comment 3 Aliaksei Urbanski 2024-10-08 13:48:11 UTC]

Created attachment 905108 [details]
backtrace

[Comment 4 Aliaksei Urbanski 2024-10-08 13:50:37 UTC]

Created attachment 905109 [details]
thread apply all bt full

[Comment 5 Aliaksei Urbanski 2024-10-08 17:21:07 UTC]

By the way, emerge world -uav doesn't freeze without -DN.

[Comment 6 Sam James 2024-10-08 17:22:41 UTC]

How about pdb?

[Comment 7 Aliaksei Urbanski 2024-10-08 17:23:32 UTC]

Created attachment 905111 [details]
Python stack

[Comment 8 Aliaksei Urbanski 2024-10-08 17:25:12 UTC]

Created attachment 905112 [details]
pdb where

[Comment 9 Sam James 2024-10-08 17:36:52 UTC]

USE=jit is masked so not critical.

[Comment 10 Aliaksei Urbanski 2024-10-08 17:37:59 UTC]

Created attachment 905113 [details]
pdb where (another attempt)

[Comment 11 Aliaksei Urbanski 2024-10-08 17:49:10 UTC]

Created attachment 905114 [details]
pdb where (3rd attempt)

While it's frozen, python3.13 consumes 100% time of a single CPU core.

As you can see, first and third traces are similar while the second one is quite different from them.

[Comment 12 Zac Medico 2024-10-08 22:28:25 UTC]

If you export PYTHON_JIT=0 does it suppress the problem in emerge? It seems pretty obvious that it should, but I'm just looking for confirmation.

[Comment 13 Aliaksei Urbanski 2024-10-08 23:22:27 UTC]

> If you export PYTHON_JIT=0 does it suppress the problem in emerge?
I confirm that it suppresses the problem.
With PYTHON_JIT=0 emerge doesn't freeze.

[Comment 14 Zac Medico 2024-10-09 23:05:57 UTC]

Sounds like is maybe more of a python issue than a portage issue, and it might correct itself over time.

[Comment 15 Aliaksei Urbanski 2024-10-09 23:33:57 UTC]

> Sounds like is maybe more of a python issue than a portage issue, and it might correct itself over time.
That's true. I believe I should report this issue to the Python upstream.
Actually, it's not the only one that I found so far.
Python 3.13 with JIT gets stuck in a few more cases.

[Comment 16 Sam James 2024-10-10 14:01:05 UTC]

Please do report those upstream (and link them here), ideally for simpler applications first, thank you!

[Comment 17 Sam James 2024-10-29 20:18:42 UTC]

I see https://github.com/python/cpython/issues/126127 at least...