Can't update Homebrew because of permissions issue in Terminal

My current implementation of homebrew works fine on High Sierra and Mojave 10.14.3.

Once you have it reinstalled, you need to tweak permissions on the folders within /usr/local which is owned by root:wheel.

sudo chown -R $(whoami):admin /usr/local

This will set everything inside of /usr/local to your username and the group admin. This should be sufficient for normal operation of homebrew. However, if you do not want homebrew talking to Google Analytics, you need to gag that default with the following in your ~/.bash_profile:

export HOMEBREW_NO_ANALYTICS=1

Purposeful use of uppercase.

Regularly, I will follow this ordered workflow with brew:

brew update

brew upgrade

brew cleanup (if any prior installed packages upgraded)

That cleanup command will remove prior package version installations, and help keep storage freed up.

There is no need to use sudo, or switch directory to root when running brew.

Brute-force... First, make a complete backup of your entirely macOS environment. Then...

Remove Homebrew:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"

Re-install Homebrew:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

The older Homebrew versions didn't (don't) do well on High Sierra and Mojave, due to tightened security.

There are various previous Homebrew discussions around the 'net, though with no clear answers over in the Homebrew forums and FAQ, unfortunately.

I've been running with the following settings on /usr/local on High Sierra for quite some time, and Homebrew works just fine:

$ ls -aled /usr/local

drwxr-xr-x  21 root  wheel  714 May  2  2018 /usr/local

$ 

Changing ownership on the /usr/local directory shouldn't be necessary for Homebrew, and that change may well head toward "fun" on upgrades and quite possibly on a multi-user system.

More generally, I'd recommend against changing the ownership of a system-wide directory. Add an ACL if you really need that write access.

There's a hole in the Homebrew docs and FAQ around that particular error, and I'd suggest asking the Homebrew folks about the error directly. There have been many approaches suggested around the 'net for this and related, and some of the suggestions look stale, some look entirely problematic, and some may well hose the whole of /usr/local and which isn't restricted to Homebrew. Other apps and tools can and do use that same path.

Remove and reinstall gets you the latest bits, too.

Back up your environment. All of it. Use Time Machine, Disk Utility, or some other locally-preferred backup tool.

Remove Homebrew:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/uninstall)"

Re-install Homebrew:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

The ACL in this context is an Access Control List, and which can be a way of granting file snd directory access and without changing ownership, among other uses. Probably not necessary here, too.

As it turns out, my /usr/local permissions and ownership match what you have shown, and I certain agree with not changing the permissons on /usr/local itself — not what I erringly posted earlier, or what homebrew recommends. Within /usr/local, the folders are uid:admin, and right or wrong, this works smoothly for homebrew, or other packages that I have installed in /usr/local.

The permissions for the /usr/local directory are what MrHoffman has shown. Mine are the same. Do not change this.

My recommendation, and that of the hombrew developer, is wrong for the sudo chown -R $(whoami):admin /usr/local command. This would change the user and group of the /usr/local directory itself, instead of just the folders within it.

You would do the following:

• Change directory into /usr/local
  • cd /usr/local
• Now, recursively change the folders (and their content) within /usr/local
  • sudo chown -R $(whoami):admin
• Return to your home directory by typing cd and return
  • cd

Once that is behind you, just type the following (in order) to let homebrew do some of its housekeeping, and upgrade itself to the latest version, as well as any packages that you have previously installed. You should not need to uninstall, and then reinstall it homebrew — unless it is royally screwed up.

brew update

brew upgrade

You can see a tree diagram of all installed packages and their dependencies:

brew deps --tree --installed