意外修改了iOS SDK头文件,现在我无法在模拟器中编译

我不知道我如何修改iOS SDK文件,但 Xcode表示我已经做了.这是他们报道的.

Fatal error: file '/Applications/Xcode 2.app/Contents/Developer/Platforms/iPhonesimulator.platform/Developer/SDKs/iPhonesimulator7.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIFontDescriptor.h' has been modified since the precompiled header '/Users/m/Library/Developer/Xcode/DerivedData/ModuleCache/24CDWDK5BTYJE/UIKit.pcm' was built
note: after modifying system headers,please delete the module cache at '/Users/m/Library/Developer/Xcode/DerivedData/ModuleCache/24CDWDK5BTYJE'
1 error generated.

我试图找到这个DerivedData,但是不能.我也去组织者删除它,做了一个干净,即使那样,没有运气.

如何将此UIFontDescriptor.h还原到其原始格式？

解决方法

删除pcm文件

rm
“/Users/m/Library/Developer/Xcode/DerivedData/ModuleCache/24CDWDK5BTYJE/UIKit.pcm”

然后

Clean Project( Cmd+Shift+K)

问题解决了