Can you give us more information? Did you receive e.g. a specific error message?
I have the intention to try Lazarus with Xcode 5 myself, but since I want to keep a working development system I have to do this with a clone of my root partition, and I will not find the time to do this before the beginning of October. Therefore, it would be valuable if you could give us some information earlier. This includes version of Mac OS X, Lazarus, Free Pascal and, which is most important of all, what happened exactly.