It seems that shader named FRayCastTilesCS is causing issues with steam deck when PSO getting compiled on game launch.
Reproduce is simple - run cooked windows client on steam deck with default proton (which is proton9.0-4 at the moment of the post) and observer process exit with code 3, which is assert inside dxil-spirv parser.
The only workaround we’ve found so far is compiling this shader with O1 instead of O3 because crash happens only with O3, but since this shader is used pretty heavily in rendering, O1 is not an option for us.
There was no issues with 5.4 on steam deck, so I think this is regression.
not sure if the problem has already been addressed, but it seems to be an issue in at the Proton library.
We test our default demos on each engine release and we report to Valve if we found issue before the Release.
I recall another recent [similar [Content removed] reporting issue going from 5.4 to 5.6, and I think the problem was addressed in a new Proton release:
Anyway you can get more debug logging from Proton setting the launch options to `PROTON_LOG=1 %command%`.
This will creates log files in /home/deck/ named steam-$NUMBERS.log
If not already addressed I suggest to report the Proton issue directly in their repo: