smc is unable to play sounds/music without vorbis support enabled in sdl-mixer. It should therefore be checked that it is enabled before building. I have not tested it with the other versions, but 1.7 definitely needs it.
Created attachment 176651 [details, diff] Check if sdl-mixer is built with useflag vorbis I have now tested smc 1.5 which also needs vorbis enabled in sdl-mixer, so I assume the same is true for 1.6. Here is a patch modifying all smc ebuilds to check for it.
We'll fix it later with use-based deps.
bugzilla
fixed with use-based deps.