> [H]ow does glibc maintain ABI compatibility? Alias attributes?

Symbol versioning[1,2]. Kind of like aliases, but more awkward. In theory it’s not specific to glibc, in practice hardly anyone else bothers being so careful about their ABI.

Note that dynamically linked musl, which Alpine uses (I think..?), doesn’t understand symbol versioning, though I expect this will only last until the first ABI break in musl.

[1]: https://www.akkadia.org/drepper/symbol-versioning

[2]: https://maskray.me/blog/2020-11-26-all-about-symbol-versioni...