Steam: No logging, does not work in pressure vessel
By default, Steam currently uses an LD_LIBRARY_PATH that refers to the runtime. Our AppRun script works with that.
Optional right now, but probably the future default, is to use a Flatpak-like container setup, currently available as opt-in beta. We don't work with that, our own LD_LIBRARY_PATH tinkering messes up. It probably even already does harm in the current default setup, pulling in system libraries when it's not supposed to.
Furthermore, the error output of the game itself gets lost, making diagnosis difficult. We should write our own log into var/steamlog.txt.