我已将 Three20 导入现有项目，但出现此错误。
请帮忙！
Ld /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/iDesignWindows.app/iDesignWindows normal i386
cd "/Dimitrios Tragas/iPhone/iPhone Apps/iDesignWindows/Final/iDesignWindows"
setenv MACOSX_DEPLOYMENT_TARGET 10.6
setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -arch i386 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.1.sdk -L/Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator -F/Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator -filelist /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Intermediates/iDesignWindows.build/Debug-iphonesimulator/iDesignWindows.build/Objects-normal/i386/iDesignWindows.LinkFileList -mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -ObjC -all_load -Xlinker -no_implicit_dylibs -D__IPHONE_OS_VERSION_MIN_REQUIRED=30000 /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/libThree20.a /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/libThree20Core.a /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/libThree20Network.a /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/libThree20Style.a /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/libThree20UI.a /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/libThree20UICommon.a /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/libThree20UINavigator.a -framework Foundation -framework CoreGraphics -framework QuartzCore -framework UIKit -o /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/iDesignWindows.app/iDesignWindows
ld: duplicate symbol _TTCreateNonRetainingArray in /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/libThree20Core.a(TTGlobalCore.o) and /Users/Dimfiniti/Library/Developer/Xcode/DerivedData/iDesignWindows-errlwvtfnegyctbuftipdkdvyiut/Build/Products/Debug-iphonesimulator/libThree20.a(TTGlobalCore.o) for architecture i386
clang: error: linker command failed with exit code 1 (use -v to see invocation)