In this scenario, I'll have to choose which libc I want to run. These won't be portable Linux binaries in the true sense of the word; I'll have to leave Alpine out, and possibly Android, which I don't want.
Fair point - while it's certainly possible to make a decision per individual library elsewhere, libc is the one thing that really will need to be linked dynamically for glibc, and it'll freeze a minimum version into the binary (i.e. it should be built against an old version of glibc).
I don't think Android is a target in most cases of this, so this would boil down to shipping 2* binaries, one glibc and one musl.
I'd need to check how musl behaves for compatibility, I'm assuming it'll be a minimum like glibc.
All of this said - you'll need to ship multiple binaries anyway, these days: x86_64 + aarch64. Possibly more…
