It's been added since macOS 10.12 (Sierra). According to my man page. Couldn't find any authoritative sources online on that, though. However, there are several

It's been added since macOS 10.12 (Sierra). According to my man page. Couldn't find any authoritative sources online on that, though. However, there are several secondary references[0][1]. [0] https://github.com/zeromq/libzmq/issues/2175 https://github.com/zeromq/libzmq/issues/2175 [1] https://github.com/rust-lang/libc/issues/776 https://github.com/rust-lang/libc/issues/776