由于底层架构的大幅变化，苹果不支持在OS X El Capitan用Xcode 6开发的App 提交到AppStore。如果你已经进入开发的最后阶段，并且还在用Xcode 6，请使用OS X Yosemite环境。
OS X El Capitan requires Xcode 7, which includes Swift 2, native support for System Integrity Protection (SIP), app thinning, as well as the latest SDKs. When running Xcode 7 you may notice a number of syntactical changes need to be applied to your Swift 1.2 code. To help in your migration to Swift 2, Xcode 7 includes a helpful tool to re-write older Swift code for you. Just select the menu item Edit > Convert > To Latest Swift Syntax and Xcode will migrate your code to the latest Swift API and syntax.
If your code is in the late stages of development and you must stay on Xcode 6 for a little while, you will need to continue to use OS X Yosemite as your development OS. The combination of OS X El Capitan and Xcode 6 is not supported for App Store submission due to significant changes in the underlying architecture. If you need to install OS X Yosemite on another partition or external hard drive, you can download OS X Yosemite from the App Store andfollow these instructions to install it. Also note that Xcode 7 is supported on both OS X El Capitan and Yosemite.