I've actually managed to get two games to launch to a point where a log is produced. Games show as running, and logs for both are attached. Game refuses to close when told by Steam to stop.
Hello @satellaview-dev, a header only log hints that something went awry before the game itself had a chance to start. If you completely close Steam, then run steam from a terminal, does it give a hint in the terminal spew? Alternatively, you can look in the console logs in ~/.local/share/Steam/logs around the time you tell Steam to start a game.
When launching Steam from the terminal, there's not much of an indication as to what's going on. I'll still put it's output into a text file, along with the others from the location you have shown.
steam-terminal-excerpt.txt
gameprocess_log_excerpt.txt
compat_log_excerpt.txt
console-linux-excerpt.txt
The issue has been fixed by (and I wish I was joking when I say this) rebuilding gst-plugins-rs from source. Just to be safe, I did regenerate the prefixes, and games now work on both experimental, and proton-ge (tested 10-7.) The indomitable human spirit wins again.
PROTON_LOGx1 2025-06
Using latest OpenSUSE Tumbleweed (20250606), Proton 10 and Experimental (also Proton-GE 10-1 through 10-4) will not launch anything I try, no matter what drive I use.
The games get stuck in the "Launching" state and in the terminal, Proton reports that it's upgrading the prefix (in this case "from None to 10.0-105") and then does not say anything after that.
At this point, the games become unkillable as the python3 processes responsible for Proton are stuck in disk sleep, and neither I nor Steam can stop them. The only thing that can is a full system reboot.
I've tried this on Steam (native, if it changes anything) and Lutris, with the same results. Proton does not get far enough into it's process to begin logging, and because of that, the PROTON_LOG launch option is useless for now. Every other version of Proton below 10 is able to load and play games just fine.