Posted December 10, 2019
It really isn't unless you install it/overwrite system libraries. deb files are really just archives containing at least two archives called control.tar.xz, data.tar.xz. What you want is inside data.tar.xz.
http://repo.steampowered.com/steamrt-images-scout/snapshots/
which is hard to remember is linked on Valve's github page
https://github.com/ValveSoftware/steam-runtime
If you take e.g. http://repo.steampowered.com/steamrt-images-scout/snapshots/0.20191119.3/com.valvesoftware.SteamRuntime.Platform-amd64,i386-scout-runtime.tar.gz you can find the libraries in the steam-runtime/lib/i386-linux-gnu or steam-runtime/lib/x86_64-linux-gnu subdirectories.
Generally speaking the most useful problem solver for games written in C# is using LC_ALL=C before running the game if you are on a system that uses a locale setting that uses a comma as a decimal separator like de_DE@Euro in Germany.
0Grapher: How do I find it? (Do you mean this? https://www.gamingonlinux.com/articles/steam-for-linux-can-now-run-games-in-a-special-container.15384)
The download directory http://repo.steampowered.com/steamrt-images-scout/snapshots/
which is hard to remember is linked on Valve's github page
https://github.com/ValveSoftware/steam-runtime
If you take e.g. http://repo.steampowered.com/steamrt-images-scout/snapshots/0.20191119.3/com.valvesoftware.SteamRuntime.Platform-amd64,i386-scout-runtime.tar.gz you can find the libraries in the steam-runtime/lib/i386-linux-gnu or steam-runtime/lib/x86_64-linux-gnu subdirectories.
0Grapher: Regarding the LD_LIBRARY_PATH – I knew there was some kind of command like this but I didn't know it. Do you know other useful commands like this? Like setting a different path for the home or /local/share folder? That might reduce the terrible clutter in the home folder.
You could try to set XDG_DATA_HOME, XDG_CONFIG_HOME and related variables (you can look at all environment variables if you run export), but I assume that most games use hard coded paths. Generally speaking the most useful problem solver for games written in C# is using LC_ALL=C before running the game if you are on a system that uses a locale setting that uses a comma as a decimal separator like de_DE@Euro in Germany.