从XCODE 5的目录中:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs
把iPhoneOS7.1.sdk 这个文件夹拷贝到 XCODE 6的
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs
中即可.