[quesera]

A. OSX is not a single user system. It inherits from various Unixes, and no Unix has ever had nonprivileged writability on any directory under /usr.

FHS does not apply to OSX in any way. Why do people think so?

Also, /Applications is not writable by nonprivileged users either!

Agreed on ~"changes yield outrage", but in this case, it's just a software application vendor violating obvious historical and specific guidelines from software OS vendor, and people blaming OS vendor when things break. This perplexes me.

[tptacek]

You might just as productively argue that there is no such thing as a modern single-user system, since Windows isn't that either. His point is pretty clear.

OTOH: The debate here is a little confusing. What SIP is doing w/r/t/ /usr/local isn't unprecedented; securelevels and the immutable flag could have the same effect on OpenBSD all the way back in the 1990s.

[quesera]

> You might just as productively argue that there is no such thing as a modern single-user system, since Windows isn't that either. His point is pretty clear.

Correct, and nonprivileged users can't install software globally on Windows either. Because it's now a modern OS, and that's how things are done. For very good reasons.

His point, as far as I can tell, amounts to: applications should be able to trash permissions on convenient directories and not have the OS complain or repair their damage.

Perhaps I'm being ungenerous here? I apologize if so.

On re read, I realize that tptacek is responding only to the SIP part of the discussion. OK, SIP is surprising to desktop computer users. But it's a good feature that requires a little adjustment to work with. But really not much, and none for the vast majority of users who don't muck with system directories.

[tptacek]

He's arguing that users should be able to elevate their privileges by supplying root's credentials and then create a simple directory without having to reboot.

I more agree with you than with him, but his argument seems pretty straightforward.

[quesera]

Well, if you unwind far enough, I think the original discussion was about why Homebrew has trouble using /usr/local. Where "using" means "owning, adding git repos to, changing permissions on, etc".

OSX suggests /usr/local as a good location to install software, but insists that the directory itself be owned by root, and protects the parent directory /usr under SIP.

My assertion is that Homebrew is using /usr/local incorrectly (and in contravention to all expectation), and that blaming Apple for the problems thereby created is inappropriate.

I also think SIP is a good thing.