问题
I added FMDB to my project then added the frameworks libsqlite3.dylib and libsqlite3.0.dylib, but I still get the build error. If I remove the FMDB classes from my project then it builds just fine. What other things should I check?
Detailed info on the error:
Ld /Users/gmi/Library/Developer/Xcode/DerivedData/iNROMockUp5->gjmgpakyszrgwbbxnkdxehexacxm/Build/Products/Debug->iphonesimulator/iNROMockUp5.app/iNROMockUp5 normal i386 cd /iOSDev/Testing/iNROMockUp5 setenv MACOSX_DEPLOYMENT_TARGET 10.6 setenv PATH >"/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/bin:/usr/bi>n:/bin:/usr/sbin:/sbin" /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/llvm-gcc-4.2 -arch i386 >-isysroot >/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.3.sdk ->L/Users/gmi/Library/Developer/Xcode/DerivedData/iNROMockUp5->gjmgpakyszrgwbbxnkdxehexacxm/Build/Products/Debug-iphonesimulator ->F/Users/gmi/Library/Developer/Xcode/DerivedData/iNROMockUp5->gjmgpakyszrgwbbxnkdxehexacxm/Build/Products/Debug-iphonesimulator -filelist >/Users/gmi/Library/Developer/Xcode/DerivedData/iNROMockUp5->gjmgpakyszrgwbbxnkdxehexacxm/Build/Intermediates/iNROMockUp5.build/Debug->iphonesimulator/iNROMockUp5.build/Objects-normal/i386/iNROMockUp5.LinkFileList -mmacosx->version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -lsqlite3 -lsqlite3.0 -framework >MapKit -framework UIKit -framework Foundation -framework CoreGraphics -o >/Users/gmi/Library/Developer/Xcode/DerivedData/iNROMockUp5->gjmgpakyszrgwbbxnkdxehexacxm/Build/Products/Debug->iphonesimulator/iNROMockUp5.app/iNROMockUp5
ld: duplicate symbol _main in /Users/gmi/Library/Developer/Xcode/DerivedData/iNROMockUp5->gjmgpakyszrgwbbxnkdxehexacxm/Build/Intermediates/iNROMockUp5.build/Debug->iphonesimulator/iNROMockUp5.build/Objects-normal/i386/fmdb.o and >/Users/gmi/Library/Developer/Xcode/DerivedData/iNROMockUp5->gjmgpakyszrgwbbxnkdxehexacxm/Build/Intermediates/iNROMockUp5.build/Debug->iphonesimulator/iNROMockUp5.build/Objects-normal/i386/main.o for architecture i386 collect2: ld returned 1 exit status Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/llvm-gcc-4.2 failed >with exit code 1
ld: duplicate symbol _main in /Users/gmi/Library/Developer/Xcode/DerivedData/iNROMockUp5->gjmgpakyszrgwbbxnkdxehexacxm/Build/Intermediates/iNROMockUp5.build/Debug->iphonesimulator/iNROMockUp5.build/Objects-normal/i386/fmdb.o and >/Users/gmi/Library/Developer/Xcode/DerivedData/iNROMockUp5->gjmgpakyszrgwbbxnkdxehexacxm/Build/Intermediates/iNROMockUp5.build/Debug->iphonesimulator/iNROMockUp5.build/Objects-normal/i386/main.o for architecture i386
Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/llvm-gcc-4.2 failed with exit code 1
回答1:
Remove fmdb.m from your project and you will be fine.
回答2:
Remove main.m from your project and you will be fine.
来源：https://stackoverflow.com/questions/6876453/apple-mach-o-id-linker-error-when-adding-external-libraries-to-project