[mzs]

I see what you are saying but please step back and take a wider view for a moment.

Even assuming OSX is a single user system (which is arguable), it is 2015 and should that single user be able to accidentally damage /usr/local? I think not, that by today an OS should help protect you from broken postinstall script or what not.

Moreover please think about this: homebrew is not wanting /usr/local/ root:admin but instead /usr/local/ `/usr/bin/whoami`:admin.

Further even on our laptops where there is just one user, I use a non-admin user. I have no problems using FUS, GUI prompted temporary admin permissions, or /usr/bin/login -p and sudo day-to-day, but homebrew has a problem with sudo.

Apple SIP has no problem with /usr/local/ 0:0 but homebrew does. Because of shortcuts homebrew has forced a number of poor decisions on it's users.