Can't install for multiple users

[pokidyshev]

Hi!

I'm trying to install brew for 2 admin users on latest Big Sur. I've tried almost every approach from stackoverflow but they all come down to these simple commands:

chgrp -R admin /usr/local/*
chmod -R g+w /usr/local/*

This does the job for the user which executes the commands. While the other user always gets these errors on brew update:

...
error: unable to unlink old 'Library/Homebrew/vendor/bundle/ruby/2.6.0/gems/rubocop-rails-2.10.1/lib/rubocop/rails/inject.rb': Permission denied
error: unable to unlink old 'Library/Homebrew/vendor/bundle/ruby/2.6.0/gems/rubocop-rails-2.10.1/lib/rubocop/rails/schema_loader.rb': Permission denied
error: unable to unlink old 'Library/Homebrew/vendor/bundle/ruby/2.6.0/gems/rubocop-rails-2.10.1/lib/rubocop/rails/schema_loader/schema.rb': Permission denied
error: unable to unlink old 'Library/Homebrew/vendor/bundle/ruby/2.6.0/gems/rubocop-rails-2.10.1/lib/rubocop/rails/version.rb': Permission denied

What is the correct way to install Home-brew for 2 admin users?

[gromgit]

Create a third admin user (e.g. homebrew), then:

sudo chown -R homebrew:admin /usr/local/*

Then all further write operations (i.e. install, update, upgrade, etc.) should be done by everyone else as that user, by the power of su or sudo, depending on your preference:

su - homebrew brew update

In this respect, there's only one difference between Homebrew and a system package manager: the former lets you decide which user to grant ownerships to, while the latter fixes it as root.

[pokidyshev]

In that case it's just enough to run su user1 -c 'brew update', innit? No need in creating a separate user.

[gromgit]

My personal preference is to have a mission-specific account, but if user1 doesn't mind opening up her account, then as long as user1 owns the Homebrew hierarchy, that could work too.

[pokidyshev]

Thanks! It works!

[dijonkitchen]

I wasn't able to do su - some-user brew update on a new Mac with two users.

You'll need the -c 'some command' for it to work. I also wanted to note that only su works, not sudo.

TLDR: su - some-user -c 'some command'

Edit:
I was able to use sudo when adding some more flags: sudo -Hiu some-user some-long-command