Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***
Hello, I have been enjoying using my Debian Testing install, it works great for most applications, and most steam games, however, on my system I have been unable to play marvel rivals.
I attempted using 25.0.3-1 to solve this issue, this of course, did not work.
Other Games that have worked include source games (Black Mesa) lighter weight games (Balatro and Town Of Salem 2), and Xcom Enemy Unknown.
I also attempted using Proton Experimental, Proton beta 10, Proton GE 10.1, and Proton GE 9-27, none of these made it launch, either. This could be a nothingburger, but considering this game is popular, it might be worth looking into? It, in all honesty, is probably fixed upstream already.

I would suggest getting a Proton log for this by setting environment
variable PROTON_LOG=1 and looking for the log in ~/steam-2767030.log (see
https://github.com/ValveSoftware/Proton/) which would include any error
messages that the game produces. That would help to establish whether
it's a driver bug, a Proton bug, a game bug or something else.

One possibility is that it's the same issue I reported in
https://bugs.debian.org/1107633, which is a Mesa bug.

Another possibility is that it might be the bug fixed by
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/34774,
which is fixed in 25.0.6 upstream (see also #1105831).

Or it might be some other Mesa issue, or it might be nothing to do with
Mesa at all. It isn't possible to tell which from the information
provided here so far.

Thanks,
     smcv