xcode-select: Error: No Xcode folder is set. ってエラーが出たので

Xcode 4.3インストール後にgit diffしたらこんなエラーが出た。

$ git diff HEAD
xcode-select: Error: No Xcode folder is set. Run xcode-select -switch
Error: /usr/bin/xcode-select returned unexpected error.
external diff died, stopping at hoge.rb.

以下コマンドを実行すればOK

$ sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer