objective c - Duplicate Symbol Error

Question

I'm not sure what I did but I added an IBOutlet to display an additional attribute in a TableView cell. When building the application I get the following error message...

Ld /Users/roberthill/Library/Developer/Xcode/DerivedData/PHAInspect-awfhtfopjdgfmsdsjfjivdnlzgir/Build/Products/Debug-iphonesimulator/PHAInspect.app/PHAInspect normal i386
    cd /Users/roberthill/Documents/PHAInspect
    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/clang -arch i386 -isysroot /Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.0.sdk -L/Users/roberthill/Library/Developer/Xcode/DerivedData/PHAInspect-awfhtfopjdgfmsdsjfjivdnlzgir/Build/Products/Debug-iphonesimulator -F/Users/roberthill/Library/Developer/Xcode/DerivedData/PHAInspect-awfhtfopjdgfmsdsjfjivdnlzgir/Build/Products/Debug-iphonesimulator -filelist /Users/roberthill/Library/Developer/Xcode/DerivedData/PHAInspect-awfhtfopjdgfmsdsjfjivdnlzgir/Build/Intermediates/PHAInspect.build/Debug-iphonesimulator/PHAInspect.build/Objects-normal/i386/PHAInspect.LinkFileList -mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -fobjc-arc -Xlinker -no_implicit_dylibs -D__IPHONE_OS_VERSION_MIN_REQUIRED=50000 -framework CoreData -framework UIKit -framework Foundation -framework CoreGraphics -o /Users/roberthill/Library/Developer/Xcode/DerivedData/PHAInspect-awfhtfopjdgfmsdsjfjivdnlzgir/Build/Products/Debug-iphonesimulator/PHAInspect.app/PHAInspect

ld: duplicate symbol _OBJC_METACLASS_$_Inspection in /Users/roberthill/Library/Developer/Xcode/DerivedData/PHAInspect-awfhtfopjdgfmsdsjfjivdnlzgir/Build/Intermediates/PHAInspect.build/Debug-iphonesimulator/PHAInspect.build/Objects-normal/i386/Inspection-AEDA73D75B42426A.o and /Users/roberthill/Library/Developer/Xcode/DerivedData/PHAInspect-awfhtfopjdgfmsdsjfjivdnlzgir/Build/Intermediates/PHAInspect.build/Debug-iphonesimulator/PHAInspect.build/Objects-normal/i386/Inspection-AEDA73D75B42426A.o for architecture i386
Command /Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/clang failed with exit code 1

I tried backing out the changes to add the IBOutlet but I'm still getting this error message.

I checked other similar posts but I don't think the conditions are the same (I could be wrong though). Any ideas?

Answer 1

I had a similar issue:

ld: duplicate symbol _OBJC_METACLASS_$_MyClass1 in /Users/.../MyClass2.o and /Users/.../MyClass1.o for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

And finally the reason was that inside MyClass2.m I wrote:

#include "MyClass1.m"

Instead of

#include "MyClass1.h"

It's hard to find when you have a lot of #include statements inside your .m file.