Setting the GKLocalPlayer authentication handler causes large spew on log output.

In my ObjectiveC-based macOS app, I set the GKLocalPlayer authentication handler:

Code Block 
   GKLocalPlayer* player = [ GKLocalPlayer localPlayer ];
   player.authenticateHandler = ^(NSViewController * _Nonnull viewController, NSError *error)
	{
        ....

And when I do this, I get a large spew of what seems a call stack printed on the app log?

Code Block 
["$s7Combine10PublishersO12HandleEventsV5Inner33_9464E9048FC4C9C669F954B681B5AD45LLC6cancelyyF +84", "$s7Combine10PublishersO12HandleEventsV5Inner33_9464E9048FC4C9C669F954B681B5AD45LLCy_x_qdGAA11CancellableA2aJP6cancelyyFTW +24", "$s7Combine10PublishersO7FlatMapV5Outer33_E91C3F00A6DFAAFEA2009FAF507AE039LLC6cancelyyF +944", "$s7Combine10PublishersO7FlatMapV5Outer33_E91C3F00A6DFAAFEA2009FAF507AE039LLCy_xqqdGAA11CancellableA2aJP6cancelyyFTW +24", "$s7Combine14ReduceProducerC7receiveyAA11SubscribersO6DemandVq_F +1100", "$s7Combine14ReduceProducerCyxq_q0_q1_q2_GAA10SubscriberA2aEP7receiveyAA11SubscribersO6DemandV5InputQzFTW +24", "$s7Combine10PublishersO7FlatMapV5Outer33_E91C3F00A6DFAAFEA2009FAF507AE039LLC12receiveInneryAA11SubscribersO6DemandV6OutputQz_SitF +336", "$s7Combine10PublishersO7FlatMapV5Outer33_E91C3F00A6DFAAFEA2009FAF507AE039LLC4SideV7receiveyAA11SubscribersO6DemandV6OutputQzF +24", "$s7Combine10PublishersO8SequenceV5Inner33_8116E0FA2B2A13BBC974430F9C6D956ELLC7requestyyAA11SubscribersO6DemandVF +2000", "$s7Combine10PublishersO8SequenceV5Inner33_8116E0FA2B2A13BBC974430F9C6D956ELLCy_xqqdqd_0_qd_1_GAA12SubscriptionA2aJP7requestyyAA11SubscribersO6DemandVFTW +24", "$s7Combine10PublishersO7FlatMapV5Outer33_E91C3F00A6DFAAFEA2009FAF507AE039LLC12receiveInner12subscription_yAA12Subscription_p_SitF +264", "$s7Combine10PublishersO7FlatMapV5Outer33_E91C3F00A6DFAAFEA2009FAF507AE039LLC4SideV7receive12subscriptionyAA12Subscription_p_tF +24", "$s7Combine10PublishersO8SequenceV7receive10subscriberyqd_t7FailureQydRs_AA10SubscriberRd5InputQyd7ElementRtzlF +948", "$s7Combine9PublisherPAAE9subscribeyyqdAA10SubscriberRd7FailureQydAFRtz5InputQyd6OutputRtzlF +1012", "$s7Combine10PublishersO7FlatMapV5Outer33_E91C3F00A6DFAAFEA2009FAF507AE039LLC7receiveyAA11SubscribersO6DemandV6OutputQy_F +428", "$s7Combine10PublishersO7FlatMapV5Outer33_E91C3F00A6DFAAFEA2009FAF507AE039LLCy_xqqdGAA10SubscriberA2aJP7receiveyAA11SubscribersO6DemandV5InputQzFTW +24", "$s7Combine10PublishersO12HandleEventsV5Inner33_9464E9048FC4C9C669F954B681B5AD45LLC7receiveyAA11SubscribersO6DemandV6OutputQzF +160", "$s7Combine10PublishersO12HandleEventsV5Inner33_9464E9048FC4C9C669F954B681B5AD45LLCy_x_qdGAA10SubscriberA2aJP7receiveyAA11SubscribersO6DemandV5InputQzFTW +24", "$s7Combine6FutureC7Conduit33_3AE68DE9BADC00342FC052FEBC7D3BA6LLC7fulfillyys6ResultOyxq_GF +1232", "$s7Combine6FutureC7Conduit33_3AE68DE9BADC00342FC052FEBC7D3BA6LLC5offeryyxF +240", "$s7Combine6FutureC7promise33_3AE68DE9BADC00342FC052FEBC7D3BA6LLyys6ResultOyxq_GFyAA11ConduitBaseCyxq_GXEfU_TA +48", "$s7Combine11ConduitListO7forEachyyyAA0B4BaseCyxq_GKXEKF +244", "$s7Combine6FutureC7promise33_3AE68DE9BADC00342FC052FEBC7D3BA6LLyys6ResultOyxq_GF +776", "$s7Combine6FutureCyACyxq_Gyys6ResultOyxq_GcccfcyAGcfU_TA +28", "keypath_get_selector_showHighlights +5200", "block_destroy_helper.57 +1108", "block_destroy_helper.57 +14256", "block_destroy_helper.57 +14792", "65+[GKLeaderboard loadHighlightsWithPlayerScope:timeScope:handler:]_block_invoke_2 +348", "93-[GKLeaderboard loadEntriesWithGameDescriptor:playerScope:timeScope:range:completionHandler:]_block_invoke.269 +208", "39-[GKDispatchGroup notifyOnQueue:block:]_block_invoke.58 +36", "_dispatch_call_block_and_release +32", "_dispatch_client_callout +20", "_dispatch_main_queue_callback_4CF +1024", "CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE +16", "CFRunLoopRun +2508", "CFRunLoopRunSpecific +600", "RunCurrentEventLoopInMode +292", "ReceiveNextEventCommon +320", "_BlockUntilNextEventMatchingListInModeWithFilter +76", "_DPSNextEvent +868", "-[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] +1312", "Cocoa_PumpEvents +140", "SDL_WaitEventTimeout_REAL +316", "_ZN3Sys11InputUpdateEv +160", "_ZN3Vis10HandleMenuEf +72", "_Z13mainloop_tickv +364", "main +1036", "start +4"]

I cannot detect an actual error in this mega-long message, and the functionality seems unaffected as well? (The handler is called without error, btw, and results in an authenticated player.)

The message goes away if I remove the authentication handler.

Still, it is disconcerting that it barfs that up.

What is going on here?

Thanks!