Homebrew is “The missing package manager for OS X”. It’s pretty great. Unfortunately, upgrading to OS X Yosemite might break it, as it did for me.

There are several paths for fixing it, depending on when you realize it’s broken. Here are a few possible fixes that you can use.

If you just want the bottom line, here it is:

1. If you still haven’t upgraded to OS X Yosemite, run brew update before the OS X upgrade.
2. If you already upgraded OS X and your Homebrew is broken, run git pull from /usr/local, and then run brew update.

Read on for more details on my experience with the break and fix.