[Wayland] Project Crashes on XInitThreads

[CalebMostyn]

Tested versions

4.5-stable, 4.4.1-stable, 4.4-stable

System information

Ubuntu 24.04, Wayland - Vulkan 1.4.305 - Forward+ - Using Device #0: Intel - Intel(R) HD Graphics 630 (KBL GT2)

Issue description

When using the X11 display driver on Ubuntu 24.04 running Wayland, the exported project randomly crashes due to XInitThreads. This usually happens within an hour or so, but has gone upwards of a day before crashing.

[2025-11-19 16:27:50] [xcb] Unknown sequence number while awaiting reply
[2025-11-19 16:27:50] [xcb] You called XInitThreads, this is not your fault
[2025-11-19 16:27:50] [xcb] Aborting, sorry about that.
[2025-11-19 16:27:50] cuwb-viewer: ../../src/xcb_io.c:374: poll_for_response: Assertion `!xcb_xlib_threads_sequence_lost' failed.

This will not happen on Ubuntu 22.04 or older, also running Wayland. On older Ubuntu I have seen uptimes of over a week with no issue. It also presumably does not occur using Wayland as the display driver as it is an xcb issue, but other issues with that prevent that as being optimal.

This issue has been long occurring, and I have seen it essentially from the moment this was ran on 24.04 with Wayland. The assumption was that this was a duplicate of #75308, so when #106798 was cherry-picked for 4.5 I tested an upgrade to see if the issue still occurred, assuming it would be fixed but seemingly it has not. I am currently testing a suggestion someone made to run the executable with taskset -a -c 0, but again this is likely not optimal even if it does work as it will almost guarantee a performance hit.

Steps to reproduce

I'm not certain there is a reliable way to reproduce this other than it has consistently only happened on Wayland and 24.04, not X11 native or other versions of Ubuntu. The issue occurs both when things are happening within the program and when there is not.

Minimal reproduction project (MRP)

Presumably this would happen with any project with this setup, but I have not tested this. This project is somewhat unique as it utilizes some background threads for networking, and these use C# standard library threads, but as this is a display thread issue I would assume that is not relevent.

[AThousandShips]

What makes this different from #75308? That one is still open and wasn't marked as fixed by #106798, can you test with 4.6.dev4, you say you use 4.5, did you mean 4.5.1? 4.5 doesn't contain that PR, it's only in 4.5.1

[CalebMostyn]

I had not realized that the fix had not closed the issue entirely nor that it was not in on 4.5.0 but 4.5.1, if I can't reproduce on 4.5.1 > then this is not any different. My assumption had been that the fix was in on the version I was using and thus it may have been a different issue presenting itself the same.

[AThousandShips]

Cherry picking means it is added after a version has been released, so it would not be in 4.5 if it was cherry-picked to 4.5 (in this case that PR has a version in 4.5.1, but in some cases depending on the timing it might not be in the latest version either because it was cherry-picked after the last patch was released)

But if you are able to test with 4.5.1 or 4.6.dev4 that would help pin down if this is fixed by that PR, and if it is related to the other issue