Hi,
This issue is found in the TeXLive installer, which uses config.guess to determine the os type. The maintainer asks me to report the issue here. More info can be found at
https://tug.org/pipermail/tex-live/2020-November/046308.html
Due to a recent change (
https://github.com/TeX-Live/installer/commit/ff98be775bf48aa576cbc25aa337dd5626af6550), the config.guess will incorrectly report `x86_64-pc-linux-gnu` instead of `x86_64-pc-linux-musl` for alpine docker image.
To fix the problem, may I suggest to keep the original detection script using ldd. The reason is that the compiler is not installed in a fresh alpine docker image. Whereas, the ldd is available by default. Therefore, I think using ldd to detect musl libc is much reliable.