Hello @NIGRELOID, this reads like an issue with the Steam client, not Proton itself, and is already being tracked as a feature request at https://github.com/ValveSoftware/steam-for-linux/issues/6443. Closing in as a duplicate.
proton experimentalx1 2021-04PROTON_DEBUG_DIR=somedirx1 2021-04PROTON_DUMP_DEBUG_COMMANDS=1x1 2021-04PROTON_NO_ESYNC=1x1 2021-04PROTON_NO_ESYNC=1`x1 2021-04PROTON_NO_FSYNC=1x1 2021-04
Game ID: 9420, proton experimental
When starting proton game from shell it doesn't respect environment variables i passed to it via env or export command:
PROTON_DUMP_DEBUG_COMMANDS=1 PROTON_NO_ESYNC=1Tried launching it using url, like steam://run/9420//PROTON_DEBUG_DIR=somedir PROTON_DUMP_DEBUG_COMMANDS=1 PROTON_NO_ESYNC=1 %25command%25/
It showed this dialog, but the game started as if i didnt provided any launch options at all (heavy lags because of esync and no debug output)
steam -applaunch 9420 PROTON_NO_ESYNC=1 PROTON_NO_FSYNC=1 PROTON_DUMP_DEBUG_COMMANDS=1 prime-run %command% was useless too
Could try to edit localconfig.vdf, but that solution is a bit hacky and requires a working config parser.
Using steam GUI is not the option.