New comment by ericonr on void-packages repository

https://github.com/void-linux/void-packages/issues/17687#issuecomment-742594314

Comment:
This happened because libstdc++'s locale code is cursed, and their generic locale impl doesn't even exist properly, and that's the one used for musl targets.

If you catch the exception it all works fine (other applications like snapper use C++ locales but inside a try-catch block). There's been some light discussion on fixing this in libstdc++, but nothing has moved forward yet.