Installing in Homebrew errors
RubyPermissionsRvmHomebrewRuby Problem Overview
Attempting to install rvm and ruby 1.9.2
I already installed homebrew and git, but couldn't get complete updates because I kept getting permission errors. Re-installed Snow Leopard and repaired permissions.
Now this happens...
>$ brew install wget > >Error: Cannot write to /usr/local/Cellar
Ruby Solutions
Solution 1 - Ruby
>sudo chown -R $USER /usr/local
You'll have to give yourself ownership of /usr/local/ using that line right there. I had to do this myself after using the ruby one-liner at the top of the official docs to install Homebrew. Worked like a charm for me. It ought to be the only time you'll ever need to sudo with Homebrew.
I'm not sure if the ruby one-liner does this. If it did, then something else on my system took control of /usr/local since.
Edit: I completely missed this, but @samvermette didn't (see replies to my answer): if you run this command above and have something installed via homebrew that requires special user permissions, like mysql, make sure to give those permissions back (as the above command gives recursive ownership to everything inside /usr/local to you ($USER). In the case of mysql, it's…
> sudo chown -RL mysql:mysql /usr/local/mysql/data
Solution 2 - Ruby
I had this issue after upgrading to Mavericks, and this page was the top search result when googling the error message. I continued searching and found [this answer on stack overflow.com][1]. Put concisely, it is:
sudo chmod a+w /usr/local/Cellar
This fixed the issue for me, and as it only changes permissions for the specific path referenced in the error message, seemed unlikely to have negative side effects with other installations.
I'm putting this answer here for anyone else who may find this page first like I did. However, credit should go to [jdi][2].
[1]: https://stackoverflow.com/questions/9800527/homebrew-install-permissions-issue "here" [2]: https://stackoverflow.com/users/496445/jdi
Solution 3 - Ruby
You can allow only Admin users writing into /usr/local/?
chgrp -R admin /usr/local
chmod -R g+w /usr/local
chgrp -R admin /Library/Caches/Homebrew
chmod -R g+w /Library/Caches/Homebrew
Since that each user who belongs to Admin group, will be able to install new dependencies.
Solution 4 - Ruby
On High Sierra you need the following command cause chown will not work:
> sudo chown -R $(whoami) $(brew --prefix)/*
Link:
Solution 5 - Ruby
uninstall and re install HomeBrew that will do the trick
Solution 6 - Ruby
I suggest ensuring that the current user is a member of the group that owns /usr/local. I believe by default, that group is wheel. To make yourself a member of that group:
$ sudo dscl . append /Groups/wheel GroupMembership $USER
Although something of an inelegant hammer, it has the intended effect - enabling access to items in /usr/local that are intended only for use (read/write) by elevated members. This approach has benefits of the other above because it takes advantage of the group memberships, enabling multiple (authorized) users on the system to use homebrew.
Solution 7 - Ruby
How did you install Homebrew? Their official installation instructions include running a ruby script. That should take care of the permission issues for you.
If you don't want to run a script, there is a section of that page called "Installing to /usr/local for Developers" that explains the change in permissions needed for the /usr/local directory.
Solution 8 - Ruby
EDIT: As mentioned in the comments it's a bad idea to use sudo with homebrew, so don't use the following answer!
You can also prevent this error if you execute the command with sudo:
$ sudo brew install wget
But take care of using sudo because you can make a lot of mistakes.