duplicate symbols for architecture arm64 (Xcode error)

比如

duplicate symbol _NewBase64Encode_soomla in: /Users/UnityGame/Libraries/Plugins/iOS/Soomla/libSoomlaiOSCore.a(NSData-Base64.o) /Users/UnityGame/Libraries/Plugins/iOS/SoomlaShared/libKeeva.a(NSData-Base64.o) duplicate symbol _NewBase64Decode_soomla in: /Users/UnityGame/Libraries/Plugins/iOS/Soomla/libSoomlaiOSCore.a(NSData-Base64.o) /Users/UnityGame/Libraries/Plugins/iOS/SoomlaShared/libKeeva.a(NSData-Base64.o) duplicate symbol _OBJC_CLASS_$_FBEncryptorAES in: /Users/UnityGame/Libraries/Plugins/iOS/Soomla/libSoomlaiOSCore.a(FBEncryptorAES.o) /Users/UnityGame/Libraries/Plugins/iOS/SoomlaShared/libKeeva.a(FBEncryptorAES.o) duplicate symbol _OBJC_METACLASS_$_FBEncryptorAES in: /Users/UnityGame/Libraries/Plugins/iOS/Soomla/libSoomlaiOSCore.a(FBEncryptorAES.o) /Users/UnityGame/Libraries/Plugins/iOS/SoomlaShared/libKeeva.a(FBEncryptorAES.o) ld: 4 duplicate symbols for architecture arm64 clang: error: linker command failed with exit code 1 (use -v to see invocation)

再比如

Ld /Users/pnawale/Library/Developer/Xcode/DerivedData/hub-afxxzaqisdfliwbzxbixsaifljcl/Build/Products/Debug-iphoneos/hub.app/hub normal armv7
    cd /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub
    setenv IPHONEOS_DEPLOYMENT_TARGET 5.0
    setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.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 armv7 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.1.sdk -L/Users/pnawale/Library/Developer/Xcode/DerivedData/hub-afxxzaqisdfliwbzxbixsaifljcl/Build/Products/Debug-iphoneos -L/Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/ZBarSDK -L/Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/Infosound/Lib -L/Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/CrittercismSDK -L/Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub -L/Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/UserVoiceSDK-2.0.4 -L/Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/Libraries -F/Users/pnawale/Library/Developer/Xcode/DerivedData/hub-afxxzaqisdfliwbzxbixsaifljcl/Build/Products/Debug-iphoneos -F/Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub -filelist /Users/pnawale/Library/Developer/Xcode/DerivedData/hub-afxxzaqisdfliwbzxbixsaifljcl/Build/Intermediates/hub.build/Debug-iphoneos/hub.build/Objects-normal/armv7/hub.LinkFileList -dead_strip -ObjC -all_load -fobjc-arc -fobjc-link-runtime -miphoneos-version-min=5.0 -lMPOAuthMobile -lsbjson-ios -framework LayarSDK -framework Social -framework AddressBook -framework AddressBookUI -framework UIKit -framework QuartzCore -framework Twitter -framework SystemConfiguration -framework Security -framework OpenAL -framework OpenGLES -framework MessageUI -framework MediaPlayer -framework Foundation -framework CoreGraphics -lc++ -framework CoreTelephony -framework CoreVideo -framework CoreMotion -framework CoreMedia -framework CoreLocation -framework CoreData -framework CoreAudio -framework CFNetwork -framework AVFoundation -framework AudioToolbox -lxml2 -liconv -lz -framework MobileCoreServices -lzbar -linfosound -lCrittercism_v3_4_6 -lUserVoice -o /Users/pnawale/Library/Developer/Xcode/DerivedData/hub-afxxzaqisdfliwbzxbixsaifljcl/Build/Products/Debug-iphoneos/hub.app/hub

duplicate symbol _jpeg_free_large in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemname.o)
duplicate symbol _jpeg_free_small in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemname.o)
duplicate symbol _jpeg_get_large in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemname.o)
duplicate symbol _jpeg_get_small in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemname.o)
duplicate symbol _jpeg_mem_available in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemname.o)
duplicate symbol _jpeg_mem_init in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemname.o)
duplicate symbol _jpeg_mem_term in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemname.o)
duplicate symbol _jpeg_open_backing_store in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemname.o)
duplicate symbol _jpeg_free_large in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemnobs.o)
duplicate symbol _jpeg_free_small in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemnobs.o)
duplicate symbol _jpeg_get_large in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemnobs.o)
duplicate symbol _jpeg_get_small in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemnobs.o)
duplicate symbol _jpeg_mem_available in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemnobs.o)
duplicate symbol _jpeg_mem_init in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemnobs.o)
duplicate symbol _jpeg_mem_term in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemnobs.o)
duplicate symbol _jpeg_open_backing_store in:
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemansi.o)
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jmemnobs.o)
duplicate symbol _main in:
    /Users/pnawale/Library/Developer/Xcode/DerivedData/hub-afxxzaqisdfliwbzxbixsaifljcl/Build/Intermediates/hub.build/Debug-iphoneos/hub.build/Objects-normal/armv7/main.o
    /Users/pnawale/Documents/Paresh/Yamaha_iPhone/Code/Final/hub/LayarSDK.framework/LayarSDK(jpegtran.o)
ld: 17 duplicate symbols for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)


解决方案

1. The duplicated Function/Class is defined at two different places/files in the project and only one of them was supposed to compile for any variation of build command. But somehow both those files got compiled in your project. So you need to check your if-else conditions or other dependencies which adds src files to the list of files needed to be compiled and remove the un-needed file for your particular build command.

2. The duplicated Function/Class is defined accidentally at two different places/files in the project. Remove the wrong definition.

3. Clean your OBJ directory before you build again, there could be some old obj files in there from your previous builds which might be causing this conflict. 

P.S i am no expert, but this is how i solved this problem when i faced it.

本人在集成高德地图的时候遇到过，说明静态库里面引用重复了，所以有些静态库是不能共存的。