Some Proton games do not work after system upgrade

[Pistos]

Compatibility Report

• Name of the game with compatibility issues: Guild Wars 2, Kingdom Come: Deliverance, Horizon Zero Dawn Complete Edition
• Steam AppID of the game: 1284210, 379430, 1151640

System Information

• GPU: Radeon RX 580
• Video driver version: Mesa 24.0.7
• Kernel version: 6.6.30 (Gentoo Linux)
• Link to full system information report as Gist: https://gist.github.com/Pistos/748b68e2d12d1b750e1a182879c89ab3
• Proton version: 9, but also tried Experimental and 8

I confirm:

• [ ] that I haven't found an existing compatibility report for this game.
• There is the Guild Wars 2 issue, but I think my problem applies to multiple games for the same reason
• [x] that I have checked whether there are updates for my system available.

Steam log for GW2 also included in the same gist

Symptoms

For Guild Wars 2 and Horizon Zero Dawn, the game crashes right away with a Windows/WINE-styled dialogue window. For GW2 the crash report details given are in the same gist. Other games start up, but hang very soon.

Reproduction

1. Start one of these games
2. witness the crash or hang

Some games (like KCD) will start up okay, and seem to work, but within a few minutes will just hang. Many non-Proton games seem to work fine.

When a game hangs (such as House Flipper, game id 613100), the steam-613100.log has thousands of repetitions of these lines

I see in the steam debug info that there some issue with bubblewrap/bwrap is reported

"Child process exited with code 1: bwrap: No permissions to creating new namespace, likely because the kernel does not allow non-privileged user namespaces. On e.g. debian this can be enabled with 'sysctl kernel.unprivileged_userns_clone=1'."

but I checked, and bubblewrap is emerged with the suid USE flag, and the kernel config has user namespaces enabled:

# zcat /proc/config.gz | grep USER_NS
CONFIG_USER_NS=y

(kernel.unprivileged_userns_clone doesn't exist in Gentoo, as per https://forums.gentoo.org/viewtopic-p-8690449.html )

I happened to have a copy of my steam system info from a previous issue. The diff from then (late 2023) and now is in the same gist. One noticeable difference between the two is in the pinned_libs_32 and pinned_libs_64 sections, where we see libGLU is removed and libSDL2 is added. I don't know if that's relevant.

Some historical context: I've successfully used Steam on Linux for about 4 years now. There has been a problem related to bubblewrap before, but I was able to solve them. Games were running fine until a system upgrade (profile update) going to Gentoo profile version 23. This update involved rebuilding all packages, including such core packages as gcc, glibc, binutils, and libtool.

I'm trying to experiment with launch flags like PROTON_NO_D3D11 and PROTON_NO_ESYNC. Sometimes it helps a game start up, but it still eventually hangs.

[kisak-valve]

Hello @Pistos, there's an AMDGPU kernel module regression in 6.6.30 that was tracked at https://gitlab.freedesktop.org/drm/amd/-/issues/3343.

Use a different kernel point release.

[Pistos]

Thank you. Using Linux kernel 6.1.90 fixes things for me.