[3.12] gh-145548: Use VMADDR_CID_LOCAL in VSOCK socket tests (GH-145589)

[encukou]

Prefer VMADDR_CID_LOCAL instead of VMADDR_CID_ANY for bind() in the
server. Skip the test if bind() fails with EADDRNOTAVAIL.

Log vsock CID in test.pythoninfo.
(cherry picked from commit 6c8c72f)

Includes fix-up from 26326a0 (GH-145735)

Co-authored-by: Victor Stinner vstinner@python.org

• Issue: VSOCK test_socket.testStream() fails on aarch64 Fedora Stable 3.x buildbot #145548

[vstinner]

LGTM. I tested the change manually on Fedora Stable x86-64, ./python -m test test_socket -m ThreadedVSOCKSocketStreamTest -v pass successfully, and ./python -m test.pythoninfo works as expected (it logs test_socket.get_cid: 4294967295).

[vstinner]

The test also exists on 3.10 and 3.11, we might need to backport the change there as well.

[encukou]

The test also exists on 3.10 and 3.11, we might need to backport the change there as well.

Yes. I set the labels here, so that miss-islington includes the fix-up.

[Shrey-N]

Hiya @encukou
Here the socket prefix is missing, I think if it is a constant from the socket module, it should be namespaced. Otherwise, it couldn't safely fall back in case older systems do not have it defined.

[vstinner]

Here the socket prefix is missing, I think if it is a constant from the socket module, it should be namespaced.

I added socket.VMADDR_CID_LOCAL constant in Python 3.14. On Python 3.13 and older, the VMADDR_CID_LOCAL constant is only defined in test_socket.py.

[Shrey-N]

Ah, Thank you for the clarification :) I just realised that I didn't see the 3.12 tag