这是一个已知的错误,并在
release notes of Xcode 6 beta-5中提及(有解决方法)：
原文链接：https://www.f2er.com/swift/319646.htmlA storyboard may fail to compile after adding an NSCollectionView to
it. (17009377)!Workaround: Pick a xib that includes the NSCollectionView and load it into a Storyboard based View.!
