If you use the itch client, you don't have to do anything: it will update the game automatically and you are all set. Keep in mind that you have to have completed 8A to unlock Farewell.
LaPingvino's Games
Creator of
Recent community posts
https://www.reddit.com/r/celestegame/comments/d1ogl2/the_game_wont_launch_after_the_update_on_linux/ provides a workaround, says devs are already on it according to same bug report on Steam.
Ver 1.3.0.0
9/9/2019 2:16:09 PM
System.DllNotFoundException: libfmodstudio.so.10.14
at (wrapper managed-to-native) FMOD.Studio.System.FMOD_Studio_System_Create(intptr&,uint)
at FMOD.Studio.System.create (FMOD.Studio.System& studiosystem) [0x00005] in <0f2de739493b4f20a43a623d6fbc387c>:0
at Celeste.Audio.Init () [0x00010] in <0f2de739493b4f20a43a623d6fbc387c>:0
at Celeste.GameLoader.LoadThread () [0x0000c] in <0f2de739493b4f20a43a623d6fbc387c>:0
at Celeste.RunThread.RunThreadWithLogging (System.Action method) [0x00000] in <0f2de739493b4f20a43a623d6fbc387c>:0