我刚刚升级到xcode 4.0,我不能再部署到iPhone,我得到一个苹果Mach-O链接器错误,它仍然适用于模拟器。

    Ld /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Intermediates/iParcel.build/Debug-iphoneos/iParcel.build/Objects-normal/armv7/iParcel normal armv7
    cd /Users/yveswheeler/iParcel
    setenv IPHONEOS_DEPLOYMENT_TARGET 3.2
    setenv PATH "/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
    /Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/g++-4.2 -arch armv7 -isysroot /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk -L/Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos -F/Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos -filelist /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Intermediates/iParcel.build/Debug-iphoneos/iParcel.build/Objects-normal/armv7/iParcel.LinkFileList -dead_strip -all_load -ObjC -lxml2 -miphoneos-version-min=3.2 -framework UIKit -framework CoreGraphics -framework QuartzCore /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20.a /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20Core.a /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20Network.a /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20Style.a /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20UI.a /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20UICommon.a /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20UINavigator.a -framework AddressBook -lz.1.2.3 -framework Foundation -framework CFNetwork -framework MobileCoreServices -framework SystemConfiguration -framework MessageUI -framework AudioToolbox -o /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Intermediates/iParcel.build/Debug-iphoneos/iParcel.build/Objects-normal/armv7/iParcel

arm-apple-darwin10-g++-4.2.1: /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20.a: No such file or directory
arm-apple-darwin10-g++-4.2.1: /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20Core.a: No such file or directory
arm-apple-darwin10-g++-4.2.1: /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20Network.a: No such file or directory
arm-apple-darwin10-g++-4.2.1: /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20Style.a: No such file or directory
arm-apple-darwin10-g++-4.2.1: /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20UI.a: No such file or directory
arm-apple-darwin10-g++-4.2.1: /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20UICommon.a: No such file or directory
arm-apple-darwin10-g++-4.2.1: /Users/yveswheeler/Library/Developer/Xcode/DerivedData/iParcel-fkeqjcjcbbhjwhdssjptkdxzzzxh/Build/Products/Debug-iphoneos/libThree20UINavigator.a: No such file or directory
Command /Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/g++-4.2 failed with exit code 1

当前回答

我错误地在不同的文件中定义了一个与现有常量同名的新常量,并使用xCode 4.3.1导致了这个错误。xCode没有抱怨,但是编译器不喜欢它。

其他回答

一种可能:在Xcode 4构建设置中打开“死代码剥离”。

另一种可能性是:对于以前使用GCC的某些框架,您可能切换到使用LLVM。回到GCC(或LLVM GCC)可以消除这些警告。

我也遇到了同样的问题。

解决方案(对我来说)=检查你的框架。

在我的例子中,我添加了与CoreData相关的类,没有“CoreData.framework”。添加它解决了MACH_O的抱怨。

我在导入框架后遇到了这个问题。在“Build Phases”下面,框架的名称用红色突出显示。我再次添加框架,问题就解决了。

回复:标题中概述的问题:

以防其他人忽略了显而易见的…

在安装新版本的Xcode4并将现有文件拖到新项目中之后,我遇到了这个错误。我没有发现“添加到目标”复选框在“选择添加文件的选项:”对话框中未选中。纠正我的遗漏在目标>构建阶段>编译源解决了问题。

I struggled with this for a little while, and in my case it ended up being the Build Setting under Search Paths called FRAMEWORK_SEARCH_PATHS. It helped that I selected the "Levels" button, which seemed to compare my project, target and "Resolved" settings. I saw that my target setting somehow overrode the default of "$(inherited)", and the overridden value was what XCode "resolved" the setting to be. When I removed the override, which in this case specified the 3.2 sdk, the linker errors went away -- as did some recently appeared warnings about any classes where I called post-4.0 methods.

About those warnings -- I never saw them before I added the MessageUI framework for a recent change. I suspect, but don't know for sure, that when I added that framework, XCode tried to do something clever by adding that override to my target. I didn't do it explicitly at any point. The warnings were,for example, about the URLByAppendingPathComponent method of NSURL, which did not appear until sdk 4.0. Prior to adding the MessageUI framework, I never got that warning. And since I removed the override, I no longer get them.