我升级到 XCode 4，但我的一个项目无法再编译。有人遇到过这个问题吗？下面是完整的错误堆栈(为了易读性而稍微重新格式化):
Ld /Users/stephen/Library/Developer/Xcode/DerivedData/viewer-dsbfkuoythcgojfrsktxcccyfnuj/Build/Products/Debug-iphonesimulator/viewer.app/viewer normal i386
cd /Users/stephen/projects/Quipper/iPhone-viewer
setenv MACOSX_DEPLOYMENT_TARGET 10.6
setenv PATH "/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/g++-4.2 \
-arch i386 \
-isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.3.sdk \
-L/Users/stephen/Library/Developer/Xcode/DerivedData/viewer-dsbfkuoythcgojfrsktxcccyfnuj/Build/Products/Debug-iphonesimulator \
-L/Users/stephen/projects/Quipper/iPhone-viewer/AdMob \
"-L/Users/stephen/projects/Quipper/iPhone-viewer/Twitter+OAuth/Libraries & Headers" \
-L/Users/stephen/projects/Quipper/iPhone-viewer/FlurryLib \
-F/Users/stephen/Library/Developer/Xcode/DerivedData/viewer-dsbfkuoythcgojfrsktxcccyfnuj/Build/Products/Debug-iphonesimulator \
-filelist /Users/stephen/Library/Developer/Xcode/DerivedData/viewer-dsbfkuoythcgojfrsktxcccyfnuj/Build/Intermediates/viewer.build/Debug-iphonesimulator/viewer.build/Objects-normal/i386/viewer.LinkFileList \
-mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 \
-framework CoreGraphics -framework CoreData -lAdMob -framework iAd \
-framework StoreKit -framework MediaPlayer -lOAuth -lxml2.2 \
-framework MessageUI -framework CoreLocation -framework QuartzCore \
-framework CoreMedia -framework AVFoundation -framework SystemConfiguration \
-framework CoreAudio -framework AudioToolbox -framework Foundation \
-framework UIKit -lFlurry -framework OpenAL \
-o /Users/stephen/Library/Developer/Xcode/DerivedData/viewer-dsbfkuoythcgojfrsktxcccyfnuj/Build/Products/Debug-iphonesimulator/viewer.app/viewer
ld: duplicate symbol _OBJC_IVAR_$_StartChallengeViewController.user_pack_id
in /Users/stephen/Library/Developer/Xcode/DerivedData/viewer-dsbfkuoythcgojfrsktxcccyfnuj/Build/Intermediates/viewer.build/Debug-iphonesimulator/viewer.build/Objects-normal/i386/StartChallengeViewController-C52C140DA244D284.o
and /Users/stephen/Library/Developer/Xcode/DerivedData/viewer-dsbfkuoythcgojfrsktxcccyfnuj/Build/Intermediates/viewer.build/Debug-iphonesimulator/viewer.build/Objects-normal/i386/StartChallengeViewController-469DDEB33F89F484.o
for architecture i386
collect2: ld returned 1 exit status
Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/g++-4.2 failed with exit code 1
最佳答案
您已在 2 个不同的类中声明了具有相同名称的指定值(例如 int i = 2;)的全局 iVar，其中一个类是 StartChallengeViewController 。如果清理项目(Cmd Shift K)没有帮助，请尝试将其中一个 iVar 重命名为其他名称，或者不为其指定初始值。
关于iphone - 将项目移至 xcode 4 会出现“Apple Mach-O Linker (Id) Error”，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/6634275/