Homebrew ❤️ El Capitan

Some developers are having trouble getting up and running with homebrew after upgrading to El Capitan, thanks to a new feature called System Integrity Protection, users (even admins) no longer have writing permissions to system directories such as /usr, /etc, /bin.

Needless to say, Apple is smart enough to notice that devs would need some sort of access to a lower-level folder on the system to run binaries and root scripts, so they let /usr/local out of the lock down. That folder by default is owned by root:wheel but that can easily be changed.

Running the following command should grant you permissions to write to that folder and therefore install apps using homebrew.

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

If for some reason that fails, try running this:

sudo mkdir /usr/local && sudo chflags norestricted /usr/local && sudo chown -R $(whoami):admin /usr/local

The above steps should allow you to install homebrew and start using command-line apps.