$ brew update && brew cask install zazu Works for me... $ brew --version Homebrew 1.1.6 Homebrew/homebrew-core (git revision e517; last commit 201

$ brew update && brew cask install zazu Works for me... $ brew --version Homebrew 1.1.6 Homebrew/homebrew-core (git revision e517; last commit 2017-01-05)