How do I fix this duplicate symbol error?

Question

From the error I am getting:

ld: duplicate symbol _main in /Users/wostler/Library/Developer/Xcode/DerivedData/UIPageViewControllerDemo-hjsgatcuhsxeokdnubifybpivzum/Build/Intermediates/UIPageViewControllerDemo.build/Debug-iphonesimulator/UIPageViewControllerDemo.build/Objects-normal/i386/fmdb.o and /Users/wostler/Library/Developer/Xcode/DerivedData/UIPageViewControllerDemo-hjsgatcuhsxeokdnubifybpivzum/Build/Intermediates/UIPageViewControllerDemo.build/Debug-iphonesimulator/UIPageViewControllerDemo.build/Objects-normal/i386/main.o for architecture i386

I can't figure out why this error is occurring. I simply changed some framework files in my project and now this error won't go away! It obviously says _main is being duplicated, but I dont know where, or why?

What is causing this?

score 8 · Accepted Answer · answered Feb 09 '12 at 02:14

8

You need to look at the main.m/.h and fmdb.m/.h files. What is most likely is that they are both importing something that defines _main, perhaps at a global level. Usually thats the sort of thing that generates this error for me.

answered Feb 09 '12 at 02:14

drekka

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score 4 · Answer 2 · answered Feb 09 '12 at 02:13

4

You have two main function in your code. Do a global search for main and remove the one you don't want.

It happens when you add some other project's files to your project without remove the main function.

answered Feb 09 '12 at 02:13

Bryan Chen

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score 3 · Answer 3 · answered Feb 09 '12 at 02:21

3

Sounds like you have multiple entries under Targets/Compiled Sources. Check and remove them.

answered Feb 09 '12 at 02:21

fannheyward

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How do I fix this duplicate symbol error?

3 Answers3