Bill Bumgarner shows how to use the private _objc_setNilReceiver() function and -resolveInstanceMethod: to log the first time each selector is sent to nil. I imagine that by uncommenting the print statement in -forwardInvocation: this could be made to work with Objective-C 1.x, but you’d get a log entry for every message sent to nil. Update: … Continue reading Logging Messages to Nil