file ‘/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator7.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UITableView.h‘ has been modified since the precompiled header ‘/Users/apple/Library/Developer/Xcode/DerivedData/ModuleCache/32K330UK2N9P/UIKit.pcm‘ was built

解决办法：

/Users/lion/Library/Developer/Xcode/DerivedData/ModuleCache/32K330UK2N9P/清空，然后clean一下项目。