macOS, as shipped, is only Unix-like. Even when configured to pass UNIX certification, it doesn't qualify without the temporary waivers:

  if you want your installation of macOS 15.0 to pass the UNIX® 03 certification test suites, you need to disable System Integrity Protection, enable the root account, enable core file generation, disable timeout coalescing, mount any APFS partitions with the strictatime option, format your APFS partitions case-sensitive (by default, APFS is case-insensitive, so you’ll need to reinstall), disable Spotlight, copy the binaries uucp, uuname, uustat, and uux from /usr/bin to /usr/local/bin and the binaries uucico and uuxqt from /usr/sbin to /usr/local/bin, set the setuid bit on all of these binaries, add /usr/local/bin to your PATH before /usr/bin and /usr/sbin, enable the uucp service, and handle the mystery issues listed in the four Temporary Waivers. [1]

Maybe your installation of macOS is technically Unix, but mine sure as hell ain't. Desktop "Unix" in 2026 is little more than lipstick on a pig anyhow.

[1] https://www.osnews.com/story/141633/apples-macos-unix-certif...

▲ duskwuff 2 hours ago | parent | next [-]

As an aside:

> ... copy the binaries uucp, uuname, uustat, and uux from /usr/bin to /usr/local/bin and the binaries uucico and uuxqt from /usr/sbin to /usr/local/bin ...

This should be your hint that UNIX certification is more of a box-checking exercise than a real test of functionality. UUCP has been functionally obsolete since at least the mid-1990s; it's surprising that macOS even bothers shipping its binaries, and it's exceptionally silly that UNIX certification requires it to be present and installed in /usr/local.

	▲	wtallis an hour ago \| parent [-]
		It doesn't look like the certification requires those UUCP binaries to be in /usr/local, that's just where you have to put them on macOS to be able to `chmod +s` them, which is what the certification actually requires. Less arbitrary, but even more clearly obsolete and bad practice for a modern OS.

▲ spockz 2 hours ago | parent | prev [-]

I get most of this, but spotlight doesn’t need to be disabled altogether. That is a requirement for the verification, not the actually running as unix.