Homebrew 完全卸载

$ cd `brew --prefix`
$ rm -rf Cellar$ brew prune
$ rm -rf Library .git .gitignore bin/brew README.md share/man/man1/brew
$ rm -rf ~/Library/Caches/Homebrew

重装Homebrew

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"