This a Homebrew Tap containing a collection of "formulae" that have not yet been accepted into the mainline Homebrew repo or a different, more authoritative tap.
First, add this tap to Homebrew. This will clone the tap repository and symlink all its formulae.
brew tap nebhale/personalNow you can work on those formulae as if there were in canonical Homebrew repository:
brew install cfenv
brew install cf-build