MTBBarcodeScannerExample stopScanning backtrace

gistfile1.txt

* thread #1: tid = 0x45eb, 0x2f9b6684 libsystem_kernel.dylib`semaphore_wait_trap + 8, queue = 'com.apple.main-thread', stop reason = signal SIGSTOP
  * frame #0: 0x2f9b6684 libsystem_kernel.dylib`semaphore_wait_trap + 8
    frame #1: 0x001b7d1e libdispatch.dylib`_dispatch_semaphore_wait_slow + 190
    frame #2: 0x22fdf7ac CoreMedia`rqReceiverFinalize + 228
    frame #3: 0x2275a9f2 CoreFoundation`CFRelease + 494
    frame #4: 0x213427e8 AVFoundation`-[AVCaptureMetadataOutputInternal dealloc] + 120
    frame #5: 0x2f398d1e libobjc.A.dylib`objc_object::sidetable_release(bool) + 166
    frame #6: 0x2134299a AVFoundation`-[AVCaptureMetadataOutput dealloc] + 38
    frame #7: 0x2f398d1e libobjc.A.dylib`objc_object::sidetable_release(bool) + 166
    frame #8: 0x2f399168 libobjc.A.dylib`(anonymous namespace)::AutoreleasePoolPage::pop(void*) + 404
    frame #9: 0x258cbee8 QuartzCore`CA::Transaction::observer_callback(__CFRunLoopObserver*, unsigned long, void*) + 68
    frame #10: 0x2281b364 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 20
    frame #11: 0x22818a22 CoreFoundation`__CFRunLoopDoObservers + 278
    frame #12: 0x22818e2a CoreFoundation`__CFRunLoopRun + 914
    frame #13: 0x22765e10 CoreFoundation`CFRunLoopRunSpecific + 476
    frame #14: 0x22765c22 CoreFoundation`CFRunLoopRunInMode + 106
    frame #15: 0x29a74220 GraphicsServices`GSEventRunModal + 136
    frame #16: 0x25eef228 UIKit`UIApplicationMain + 1440
    frame #17: 0x0007fae8 MTBBarcodeScannerExample`main(argc=1, argv=0x00190aac) + 116 at main.m:16