Решение:make a backup of the ScreenSelector.so file in the Plugins folder:
cp ~/.steam/steamapps/common/Rust/rust_Data/Plugins/x86_64/ScreenSelector.so ~/.steam/steamapps/common/Rust/rust_Data/Plugins/x86_64/ScreenSelector.so.bakcopy the ScreenSelector.so file from the Legacy Branch to ...Plugins/x86_64
cp ~/.steam/steamapps/common/Rust/Legacy/rust_Data/Plugins/x86/ScreenSelector.so ~/.steam/steamapps/common/Rust/rust_Data/Plugins/x86_64/ScreenSelector.so
Launch Rust! the screen settings dialog is skipped and after a tense moment of darkness, the cilent will begin to load.
Start banging on trees and barrels with your rock!