xcode 编译错误 note: please rebuild precompiled header '/Users/wdl/Library/Developer/Xcode/DerivedData/ModuleCache/97F16MVNSP3M/UIKit-35TDUEIBFI6H.pcm'

在真机调试时遇到 atal error: file '/Applications/Xcode6.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator8.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIWebView.h' has been modified since the precompiled header '/Users/wdl/Library/Developer/Xcode/DerivedData/ModuleCache/97F16MVNSP3M/UIKit-35TDUEIBFI6H.pcm' was built

note: please rebuild precompiled header '/Users/wdl/Library/Developer/Xcode/DerivedData/ModuleCache/97F16MVNSP3M/UIKit-35TDUEIBFI6H.pcm'

1 error generated.

是由于Xcode引起的，将/Users/wdl/Library/Developer/Xcode/DerivedData/ModuleCache/97F16MVNSP3M/UIKit-35TDUEIBFI6H.pcm  即xcode 菜单Window-Organizer -DerivedData删掉即可。