Last night I upgraded to Developers Preview of OS X 10.9 Mavericks. Needless to say, Homebrew wasn’t functional anymore (unable to compile or link a library, and all that jazz). Thankfully, it’s pretty easy to get it up and running again.
First, download and install Xcode 5 Preview.
Then, open your console and execute the following command:
xcode-select --install
This will open a prompt to install CLI dev tools. Once it’s installed, your system is raring to brew once again.