MGTwitterEngine 抛出错误：g++-4.2 失败，退出代码为 1

Question

我在我的 iPhone 应用中安装了 MGTwitterEngine，并按照所有说明进行操作，现在我收到以下错误：

Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/g++-4.2 failed with exit code 1

完整的错误文本是：

Ld /Users/jason/Documents/iPad/build/Debug-iphonesimulator/FlashCards.app/FlashCards normal i386
cd /Users/jason/Documents/iPad/FlashCards
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/iPhoneSimulator4.2.sdk -L/Users/jason/Documents/iPad/build/Debug-iphonesimulator -L/Users/jason/Documents/iPad/FlashCards/Classes -L/Users/jason/Documents/iPad/FlashCards/Classes/SAOAuthTwitterEngine -L/Users/jason/Documents/iPad/FlashCards/Classes -L/Users/jason/Documents/iPad/FlashCards/Classes/Simulator4 -F/Users/jason/Documents/iPad/build/Debug-iphonesimulator -filelist /Users/jason/Documents/iPad/build/FlashCards.build/Debug-iphonesimulator/FlashCards++.build/Objects-normal/i386/FlashCards.LinkFileList -mmacosx-version-min=10.6 -l teEngine -ObjC -all_load -Xlinker -objc_abi_version -Xlinker 2 /Users/jason/Documents/iPad/core-plot/build/Debug-iphonesimulator/libCorePlot-CocoaTouch.a -framework Foundation -framework UIKit -framework CoreGraphics -framework CoreData -licucore.A -framework QuartzCore -framework SystemConfiguration -framework Security -framework MessageUI -framework CFNetwork -framework AddressBook -framework AddressBookUI -framework AudioToolbox -lteEngine -lteEngine -lOAuth -lxml2.2.7.3 -o /Users/jason/Documents/iPad/build/Debug-iphonesimulator/FlashCards.app/FlashCards

ld: duplicate symbol _EstimateBas64DecodedDataSize in /Users/jason/Documents/iPad/FlashCards/Classes/SAOAuthTwitterEngine/libOAuth.a(Base64Transcoder.o) and /Users/jason/Documents/iPad/build/FlashCards.build/Debug-iphonesimulator/FlashCards++.build/Objects-normal/i386/Base64Transcoder.o
collect2: ld returned 1 exit status
Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/g++-4.2 failed with exit code 1

知道是什么原因造成的吗？

Answer 1

链接器发现 EstimateBas64DecodedDataSize 函数的重复符号，因为在您的项目中，您试图链接到静态库 libOAuth.a 和 Base64Transcoder.o，这是从源代码构建的。它们都包含这个符号，链接器不知道应该选择哪一个。在一般情况下很难说如何解决这个问题，但基本上你必须确保这个符号是由链接器输入中的一个文件导出的。

您从哪里获得这个 MGTwitterEngine 发行版？用实际代码解决这个问题会容易得多。