iOS开发- "duplicate symbol for architecture i386 clang: error: linker command failed with exi" 解决办法

今天开发项目是, 遇到了这样一个问题（同事发给我的项目，在他的机器上可以跑，到我这就报错了）。

duplicate symbol _flag in:

/Users/apple/Library/Developer/Xcode/DerivedData/bluetoothPhone-fspknidhnizzjygmuqngfcklvnic/Build/Intermediates/bluetoothPhone.build/Debug-iphonesimulator/bluetoothPhone.build/Objects-normal/i386/DialVC.o

/Users/apple/Library/Developer/Xcode/DerivedData/bluetoothPhone-fspknidhnizzjygmuqngfcklvnic/Build/Intermediates/bluetoothPhone.build/Debug-iphonesimulator/bluetoothPhone.build/Objects-normal/i386/PersonalList.o

ld: 1 duplicate symbol for architecture i386

clang: error: linker command failed with exit code 1 (use -v to see invocation)

分析一下, 如图。



可以看出, 错误类型是 duplicate(重复) 错误标识是 _flag 错误位置在 DialVC 和 PersonalList中

于是, 搜索一下, flag。发现...



只要换掉其中一个flag就可以了。

下面的是我的报错：

duplicate symbol __notificationCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/LorUserDataViewController.o

duplicate symbol __messageCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/LorUserDataViewController.o

duplicate symbol __messageContents in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/LorUserDataViewController.o

duplicate symbol __notificationCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/AppDelegate.o

duplicate symbol __messageCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/AppDelegate.o

duplicate symbol __messageContents in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/AppDelegate.o

duplicate symbol __notificationCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/ChoiceAddressController.o

duplicate symbol __messageCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/ChoiceAddressController.o

duplicate symbol __messageContents in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/ChoiceAddressController.o

duplicate symbol __notificationCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/FeedIdeaBackController.o

duplicate symbol __messageCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/FeedIdeaBackController.o

duplicate symbol __messageContents in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/FeedIdeaBackController.o

duplicate symbol __notificationCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/FishUserDataController.o

duplicate symbol __messageCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/FishUserDataController.o

duplicate symbol __messageContents in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/FishUserDataController.o

duplicate symbol __notificationCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/HomeLoctionController.o

duplicate symbol __messageCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/HomeLoctionController.o

duplicate symbol __messageContents in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/HomeLoctionController.o

duplicate symbol __notificationCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/LoginViewController.o

duplicate symbol __messageCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/LoginViewController.o

duplicate symbol __messageContents in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/LoginViewController.o

duplicate symbol __notificationCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/FirthReginController.o

duplicate symbol __messageCount in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/FirthReginController.o

duplicate symbol __messageContents in:

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/MagessCenterController.o

/Users/Taylor/Library/Developer/Xcode/DerivedData/OMyCar-fjronizlodzryagubmjxtxismtch/Build/Intermediates/OMyCar.build/Debug-iphonesimulator/OMyCar.build/Objects-normal/i386/FirthReginController.o

ld: 24 duplicate symbols for architecture i386

clang: error: linker command failed with exit code 1 (use -v to see invocation)
而我今天遇到的问题解决办法是直接将其注释掉，因为其他地方并没有用到他们，如下：
//NSMutableArray *_messageContents;
//int _messageCount;
//int _notificationCount;