Duplicate Symbol Error in Objective-C build?

Question

I got this error when I press build+debug:

ld: duplicate symbol .objc_class_name_BlogTableItemCell in /Users/fabian/Development/Workspaces/iphone_experiments         


        

Answer 1

It seems that you are compiling the same BlogTableItemCell class two times in different places of your code. This may happen in the following cases.

• You have put the same class implementation into two different files;

• You actually have just one implementation of this class, however you are also linking in your project a framework or library containing a class whose name is exactly the same of yours.

Try finding in the whole project your class and make sure only one copy is available within your project.

Answer 2

One of our developers left the "libSoomla*" project files in there twice. I removed the duplicate soomla files, re-built, and that fixed it!

Hope it helps.

Answer 3

iPhone: Duplicate Symbol Error? by user576924

answered it correctly for me. However to find the offending gremlin this ZSH snippet.

grep "import.*\.m" **/*.[hm]

Will immediately tell you where your error is.

Answer 4

This may help someone

I got this error because I duplicate a ViewController and then renamed it. So when I compile I got this error. The reason was in both of the view controllers there was a "float" variable with same name i.e "float padding=10.0" which I had defined on class level. Renaming the name of the above mentioned variable in One of the view controllers solved my problem.

Answer 5

I just ran into this problem myself. For the list, here's another possibility:

Duplicated linking line in the project file.

I caused this merging conflicts on a SVN update, when I accidentally duplicated a line.