Hombrew try to install zsh configuration

[jcubic]

Output of brew config

HOMEBREW_VERSION: 4.5.8
ORIGIN: https://github.com/Homebrew/brew
HEAD: c19f08b3e8ea46ba94bd9315c46c0dda10ead31c
Last commit: 2 weeks ago
Branch: stable
Core tap JSON: 07 Jul 08:15 UTC
Core cask tap JSON: 07 Jul 08:15 UTC
HOMEBREW_PREFIX: /usr/local
HOMEBREW_CASK_OPTS: []
HOMEBREW_MAKE_JOBS: 12
Homebrew Ruby: 3.4.4 => /usr/local/Homebrew/Library/Homebrew/vendor/portable-ruby/3.4.4/bin/ruby
CPU: dodeca-core 64-bit kabylake
Clang: 17.0.0 build 1700
Git: 2.39.5 => /Library/Developer/CommandLineTools/usr/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.5-x86_64
CLT: 16.4.0.0.1.1747106510
Xcode: N/A

Output of brew doctor

Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: The following directories are not writable by your user:
/usr/local/share/zsh
/usr/local/share/zsh/site-functions

You should change the ownership of these directories to your user.
  sudo chown -R jjankiewicz /usr/local/share/zsh /usr/local/share/zsh/site-functions

And make sure that your user has write permission.
  chmod u+w /usr/local/share/zsh /usr/local/share/zsh/site-functions

Description of issue

Each time I install something I got an error about zsh, even that I use bash. Is there a way to tell homebrew that I don't use zsh?

[SMillerDev]

The error is that part of the permissions of your system are broken. If you use zsh is not something brew concerns itself with, it only concerns itself with "can I install things correctly".

[jcubic]

I don't use zsh, but brew give an error about it. I'm new to mac and it seems the Apple enforces using zsh. I don't want to use zsh. Why I get errors about zsh even that I don't use it?

[SMillerDev]

You get errors about brew scanning directories and finding incorrect permissions on them that are likely to cause failures in brew usage. Brew doesn't care if it's zsh or something else.

[gromgit]

To be more explicit: a fair number of Homebrew formulae install Zsh shell functions because that's what the upstream providers (and many Zsh users) expect to be made available. Installing these formulae can fail if the relevant Zsh directories aren't set up correctly.

A whole bunch of formulae (some of which overlap with the above) also install stuff for the Fish shell under /usr/local/share/fish, which is even less commonly-used than Zsh, because that's what the upstream providers (and Fish users) expect to be made available. Installing these formulae can also fail if the relevant Fish directories aren't set up correctly.

brew doctor warns about these because users have run into installation failures due to these incorrect setups.

Going back to your environment: is there a particular reasons that you can't/won't run the commands that brew doctor provides to correct the ownerships and permissions?

[jcubic]

Can I ask how multiple users can use homebrew if the system files need to be owned by a given user? This error doesn't make sense.

[gromgit]

Can I ask how multiple users can use homebrew if the system files need to be owned by a given user?

The easiest way is to create a special user (say, homebrew), then configure sudo on your system to allow only those users to run brew as user homebrew. This would only be required for commands that alter Homebrew state (typically install/upgrade/remove); all users can run, say, brew info as themselves quite readily.

This is no different from system-level package managers, except the special user in those cases is root.

This error doesn't make sense.

It makes perfect sense if you read it carefully:

Warning: The following directories are not writable by your user

Unix/macOS filesystem permissions are more granular than "one user or everyone, nothing else in between".