问题：
warning: couldn't add 'com.apple.XcodeGenerated' tag to '/Users/xxx/Library/Developer/Xcode/DerivedData/xcode4-bswxazfuwbsguiasyatbtlmvbpps/Build/Intermediates/xcode4.build': Error Domain=NSPOSIXErrorDomain Code=2 UserInfo=0x201dde680 "The operation couldn’t be completed. No such file or directory"
error: unable to create '/Users/xxx/Library/Developer/Xcode/DerivedData/xcode4-bswxazfuwbsguiasyatbtlmvbpps/Build/Intermediates' (Permission denied)
error: unable to create '/Users/xxx/Library/Developer/Xcode/DerivedData/xcode4-bswxazfuwbsguiasyatbtlmvbpps/Build/Products' (Permission denied)
Unable to create directory /Users/xxx/Library/Developer/Xcode/DerivedData/xcode4-bswxazfuwbsguiasyatbtlmvbpps/Build/Intermediates/xcode4.build/Debug-iphonesimulator/xcode4.build/Objects-normal/i386 Unable to create directory /Users/xxx/Library/Developer/Xcode/DerivedData/xcode4-bswxazfuwbsguiasyatbtlmvbpps/Build/PrecompiledHeaders/Prefix-dflnzjtztxdgjwhistrvvjxetfrg
Unable to create directory /Users/xxx/Library/Developer/Xcode/DerivedData/xcode4-bswxazfuwbsguiasyatbtlmvbpps/Build/Intermediates/xcode4.build/Debug-iphonesimulator/xcode4.build
error: couldn't create directory /Users/xxx/Library/Developer/Xcode/DerivedData/xcode4-bswxazfuwbsguiasyatbtlmvbpps/Build/Products/Debug-iphonesimulator/xcode4.app: Permission denied
error: couldn't create directory /Users/xxx/Library/Developer/Xcode/DerivedData/xcode4-bswxazfuwbsguiasyatbtlmvbpps/Build/Products/Debug-iphonesimulator/xcode4.app: Permission denied The file “Info.plist” doesn’t exist.
解决方案：
在终端中输入如下命令：sudo chmod -R 777 /Users/xxx/Library/Developer/