I had some problems with musl last year and had to back out using it for an embedded system. Typically for example, 2 threads listening to their own socket bound using REUSEPORT wouldn't work; half the connection would arrive on a thread and the second one wouldn't get anything. That scared me a bit as I was on a deadline to deliver, so I had to quickly recompile my distro with glibc, and the problem disappeared.

I really wish it worked as I like the lean&mean&precise approach they've been using!