The patch has been merged in upstream.I've made some mistake before and the patch is updated accordingly. I'll not present the final patch here since my mail server is buggy now. Please see https://github.com/libuv/libuv/pull/4748 for it.
The mistake I made was: The reason macOS works is not that it uses a special op of `fcntl`, but that its manual is wrong and it does return a value for `getsockname`. As for FreeBSD, I didn't test it.
-- Yuqian Yang <crup...@crupest.life>
