NOTE: \"Use GHUnit\" is not an acceptable answer to this question. I know most think GHUnit is better than the Xcode4 OCUnit, but that\'s not what I\'m asking about. I\'ll evalu
I had this same problem once. For some reason one of the source files for my project was also included to be compiled for the test target, which causes this link error.
By making sure that only the test-implementation files are compiled, you should be able to resolve this error. You can check this at:
TestTarget -> Build Phases -> Compile Sources