Missing Categories

On some platforms, the dynamic loader doesn’t include a shared object in a process if it doesn’t detect that the executable uses any symbols from that object. This can cause a problem for pure Objective-C shared objects, for example frameworks that add categories to existing classes, because the loader doesn’t detect the method selectors as referenced symbols.

The symptom of this problem is a runtime exception that occurs when an object receives -[NSObject doesNotRespondToSelector:].