There is no video output from Celluloid. No idea how to get debug output from it, it's not printing anything on standard out and the built-in debug shell doesn't work since that relies on video output I guess.
Okay so it does work if I run it with LIBGL_ALWAYS_SOFTWARE=1, so I guess that's a step forward. But Celluloid is supposed to just be a GUI for MPV and MPV works perfectly fine on my system, so it shouldn't be a driver issue.
