Paro aparente

Estoy persiguiendo una parada ocasional en la funcionalidad en una aplicación en la que estoy trabajando. Los síntomas se parecen a un interlocking (la operación se detiene en medio de una testing y, finalmente, se dispara un time de espera de testing). Estoy teniendo grandes problemas para localizar el problema, sobre todo porque no tengo forma de desencadenar el error; solo sucede a veces

Ahora lo atrapé en el acto, pero no estoy seguro de cómo proceder. He detenido la testing y he chivado el estado de mis queues. No soy un experto en debugging thread / queue / deadlock, pero nada aquí me parece fuera de lo común. ¿Alguien más ve algo que seguir aquí?

introduzca la descripción de la imagen aquí introduzca la descripción de la imagen aquí

Por lo que vale la pena, también he intentado muestrear el process (usando el Monitor de actividad) mientras está en este estado. Para mí, parece sorprendentemente similar a lo que Xcode me muestra:

Call graph: 2663 Thread_680518 DispatchQueue_1: com.apple.main-thread (serial) + 2663 start (in libdyld.dylib) + 1 [0x10acd5145] + 2663 main (in QReport) + 111 [0x10593b8df] main.m:16 + 2663 UIApplicationMain (in UIKit) + 1282 [0x1076198c0] + 2663 GSEventRunModal (in GraphicsServices) + 161 [0x10a0bba3e] + 2663 CFRunLoopRunSpecific (in CoreFoundation) + 470 [0x108f31366] + 2663 __CFRunLoopRun (in CoreFoundation) + 1901 [0x108f31d3d] + 2663 __CFRunLoopDoTimer (in CoreFoundation) + 1045 [0x108f6fd35] + 2663 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ (in CoreFoundation) + 20 [0x108f70174] + 2663 __NSFireDelayedPerform (in Foundation) + 387 [0x10689d1e5] + 2663 +[XCTestProbe runTests:] (in XCTest) + 182 [0x1133acb20] + 2663 -[XCTestDriver _checkForTestManager] (in XCTest) + 234 [0x11339ca8d] + 2663 -[XCTestDriver _runSuite] (in XCTest) + 269 [0x11339c060] + 2663 -[XCTestObservationCenter _observeTestExecutionForBlock:] (in XCTest) + 162 [0x1133a6edd] + 2663 __25-[XCTestDriver _runSuite]_block_invoke (in XCTest) + 56 [0x11339c129] + 2663 -[XCTest run] (in XCTest) + 260 [0x1133a9c35] + 2663 -[XCTestSuite performTest:] (in XCTest) + 379 [0x11339f08b] + 2663 -[XCTest run] (in XCTest) + 260 [0x1133a9c35] + 2663 -[XCTestSuite performTest:] (in XCTest) + 379 [0x11339f08b] + 2663 -[XCTest run] (in XCTest) + 260 [0x1133a9c35] + 2663 -[XCTestSuite performTest:] (in XCTest) + 379 [0x11339f08b] + 2663 -[XCTest run] (in XCTest) + 260 [0x1133a9c35] + 2663 -[XCTestCase performTest:] (in XCTest) + 150 [0x1133a0379] + 2663 -[XCTestCase invokeTest] (in XCTest) + 253 [0x1133a017a] + 2663 -[NSInvocation invoke] (in CoreFoundation) + 290 [0x108efec42] + 2663 __invoking___ (in CoreFoundation) + 140 [0x108efedec] + 2663 -[SynchronizationTests testCreateInspectionAndSyncAndUpdateInspectionAndSync] (in QReport Tests) + 510 [0x1132309de] SynchronizationTests.m:249 + 2663 -[QReportTestCase waitForExpectations] (in QReport Tests) + 67 [0x113250fc3] QReportTestCase.m:250 + 2663 -[XCTestCase(AsynchronousTesting) waitForExpectationsWithTimeout:handler:] (in XCTest) + 942 [0x1133ae767] + 2663 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] (in Foundation) + 275 [0x1068a0f92] + 2663 CFRunLoopRunSpecific (in CoreFoundation) + 470 [0x108f31366] + 2663 __CFRunLoopRun (in CoreFoundation) + 1287 [0x108f31ad7] + 2663 __CFRunLoopServiceMachPort (in CoreFoundation) + 212 [0x108f32624] + 2663 mach_msg (in libsystem_kernel.dylib) + 55 [0x10afd764f] + 2663 mach_msg_trap (in libsystem_kernel.dylib) + 10 [0x10afd84de] 2663 Thread_680544 DispatchQueue_2: com.apple.libdispatch-manager (serial) + 2663 _dispatch_mgr_thread (in libdispatch.dylib) + 54 [0x10ac95d94] + 2663 kevent64 (in libsystem_kernel.dylib) + 10 [0x10afde232] 2663 Thread_680545 DispatchQueue_118: parsing queue (serial) + 2663 start_wqthread (in libsystem_pthread.dylib) + 13 [0x10b00c3dd] + 2663 _pthread_wqthread (in libsystem_pthread.dylib) + 729 [0x10b00ea9d] + 2663 _dispatch_worker_thread3 (in libdispatch.dylib) + 98 [0x10ac92d59] + 2663 _dispatch_root_queue_drain (in libdispatch.dylib) + 534 [0x10ac91c85] + 2663 _dispatch_queue_invoke (in libdispatch.dylib) + 217 [0x10ac8f9a3] + 2663 _dispatch_queue_drain (in libdispatch.dylib) + 435 [0x10ac8fcb4] + 2663 _dispatch_client_callout (in libdispatch.dylib) + 8 [0x10aca5964] + 2663 _dispatch_call_block_and_release (in libdispatch.dylib) + 12 [0x10ac8af16] + 2663 __43-[DTXMessageParser initWithMessageHandler:]_block_invoke (in DTXConnectionServices) + 35 [0x1166a55a6] + 2663 -[DTXMessageParser parseMessage] (in DTXConnectionServices) + 50 [0x1166a57e8] + 2663 -[DTXMessageParser waitForMoreData:incrementalBuffer:] (in DTXConnectionServices) + 87 [0x1166a5bba] + 2663 _dispatch_semaphore_wait_slow (in libdispatch.dylib) + 213 [0x10ac93144] + 2663 semaphore_wait_trap (in libsystem_kernel.dylib) + 10 [0x10afd851a] 2663 Thread_680564: com.apple.NSURLConnectionLoader + 2663 thread_start (in libsystem_pthread.dylib) + 13 [0x10b00c3ed] + 2663 _pthread_start (in libsystem_pthread.dylib) + 176 [0x10b00efd7] + 2663 _pthread_body (in libsystem_pthread.dylib) + 131 [0x10b00f05a] + 2663 __NSThread__main__ (in Foundation) + 1194 [0x10689f09d] + 2663 +[NSURLConnection(Loader) _resourceLoadLoop:] (in CFNetwork) + 434 [0x10a712e8d] + 2663 CFRunLoopRunSpecific (in CoreFoundation) + 470 [0x108f31366] + 2663 __CFRunLoopRun (in CoreFoundation) + 1287 [0x108f31ad7] + 2663 __CFRunLoopServiceMachPort (in CoreFoundation) + 212 [0x108f32624] + 2663 mach_msg (in libsystem_kernel.dylib) + 55 [0x10afd764f] + 2663 mach_msg_trap (in libsystem_kernel.dylib) + 10 [0x10afd84de] 2663 Thread_680568: com.apple.CFSocket.private 2663 thread_start (in libsystem_pthread.dylib) + 13 [0x10b00c3ed] 2663 _pthread_start (in libsystem_pthread.dylib) + 176 [0x10b00efd7] 2663 _pthread_body (in libsystem_pthread.dylib) + 131 [0x10b00f05a] 2663 __select (in libsystem_kernel.dylib) + 10 [0x10afdd3fa] 

Cualquier sugerencia sería muy apreciada.