protonscr

Estella Demo unexpectedly runs with user's system wine

steamopen appid 41959203rd party game
ValveSoftware/steam-for-linux#12526 · opened 2025-12-05 by jn64 · updated 2026-07-03 · 1 comments · github · game page · search this game
Jjn64 2025-12-05 github

If a Windows depot is wrongly marked for Linux, it may unexpectedly run using the system wine instead of Proton.

E.g. the Estella demo at the time of writing has only 1 depot containing only a Windows build, but it is marked for both Windows and Linux https://steamdb.info/depot/4195921/ (this has since been fixed)

Steps to repro

  1. Install Estella demo on Linux
  2. Do not explicitly set a compat tool for the game
  3. Have binfmt configured to run Windows exe's with wine (probably enabled by default on mainstream distros when you install the distro's full wine package).
  4. Press Play. It will run estella.exe with your system wine.
    (Without the appropriate binfmt config, it will fail silently.)

Signs that it is running with system wine:

  • you might see the typical "updating /home/$USER/.wine" popup
  • files are created in ~/.wine/drive_c/users/$USER/AppData/Roaming/estella/ instead of Steam/steamapps/compatdata/$APPID/...
  • there are wine-related processes but no Proton processes

Obviously this is the dev/publisher error, but it also seems like it shouldn't be allowed to happen on the client side. Neither outcome (running with system wine or failing silently) is good.

Testing without the wine binfmt config

On mainstream distros[^1], there is probably a file installed at /usr/lib/binfmt.d/wine.conf (or a similar name), handled by systemd-binfmt.service. (see man binfmt.d and man systemd-binfmt)

To test disabling it:

$ sudo ln -s /dev/null /etc/binfmt.d/wine.conf
$ sudo systemctl restart systemd-binfmt.service

The game that previously ran with system wine should now fail.

To re-enable, delete /etc/binfmt.d/wine.conf and restart the service.

[^1]: On Fedora, /usr/lib/binfmt.d/wine.conf is provided by wine-systemd, which is a hard dep (requires) of the full wine package (via wine-desktop). However you won't have it if you only install the minimal wine-core.

  On Debian, `/usr/lib/binfmt.d/wine` is provided by `wine-binfmt`, which is a soft dep (suggests) of `wine`

  On Arch, `/usr/lib/binfmt.d/wine.conf` is provided by `wine`.
Jjn64 2025-12-05 github

Strange rename. Estella is just the example I encountered. This issue can happen with any game that is similarly misconfigured.

Nothing extracted yet.