I am testing my app out, pushing it pretty hard, and I'm getting it to crash (black screen, image doesn't save, drops back to springboard). However, I get no crash reports logged in the console. When I test using profiler all I get is a message saying the target died, but it gives no clues.
In the organiser I got the device crash logs which gives me this which I believe is telling me I'm sending a message to something I've released (objc-msgSend + 22)? Am I on the right track here?
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Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x576e6f69
Crashed Thread: 0
Thread 0 name: Dispatch queue: com.apple.main-thread
Thread 0 Crashed:
0 libobjc.A.dylib 0x34f8ef7e objc_msgSend + 22
1 CoreFoundation 0x371d7e90 CFRetain + 76
2 CoreFoundation 0x371e1b74 +[__NSArrayI __new::] + 48
3 CoreFoundation 0x371e1a8e -[__NSPlaceholderArray initWithObjects:count:] + 294
4 CoreFoundation 0x371e9394 -[NSArray initWithArray:range:copyItems:] + 756
5 CoreFoundation 0x371fcd5a +[NSArray arrayWithArray:] + 66
6 AVFoundation 0x335da766 -[AVCaptureSession outputs] + 146
7 AVFoundation 0x335de26e -[AVCaptureSession _doDidStop:] + 38
8 AVFoundation 0x335dfaea -[AVCaptureSession _handleNotification:payload:] + 2002
9 AVFoundation 0x335d8af6 avcaptureSessionFigRecorderNotification + 1202
10 AVFoundation 0x335fafd8 AVCMNotificationDispatcherCallback + 184
11 CoreFoundation 0x3725b7c8 __CFNotificationCenterAddObserver_block_invoke_0 + 116
12 CoreFoundation 0x3725b540 ___CFXNotificationPost_block_invoke_0 + 64
13 CoreFoundation 0x371e7090 _CFXNotificationPost + 1400
14 CoreFoundation 0x371ef1c6 CFNotificationCenterPostNotification + 102
15 CoreMedia 0x366eeeb0 CMNotificationCenterPostNotification + 112
16 Celestial 0x374b08a2 FigRecorderRemoteCallbacksServer_NotificationIsPending + 478
17 Celestial 0x374b06ba _XNotificationIsPending + 54
18 Celestial 0x374b0678 figrecordercallbacks_server + 92
19 Celestial 0x374af642 remrec_ClientPortCallBack + 146
20 CoreFoundation 0x37258f0c __CFMachPortPerform + 356
21 CoreFoundation 0x3726351c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 32
22 CoreFoundation 0x372634be __CFRunLoopDoSource1 + 134
23 CoreFoundation 0x3726230c __CFRunLoopRun + 1364
24 CoreFoundation 0x371e549e CFRunLoopRunSpecific + 294
25 CoreFoundation 0x371e5366 CFRunLoopRunInMode + 98
26 AVFoundation 0x335ef4d0 -[AVRunLoopCondition _waitInMode:untilDate:] + 348
27 AVFoundation 0x335ef36c -[AVRunLoopCondition waitUntilDate:inMode:] + 20
28 AVFoundation 0x335dc13a -[AVCaptureSession _stopPreviewing] + 438
29 AVFoundation 0x335dc2d6 -[AVCaptureSession _setRunning:] + 166
30 AVFoundation 0x335dbe42 -[AVCaptureSession stopRunning] + 274
31 zApp 0x0007e1ce 0x79000 + 20942
32 UIKit 0x30fa5b8e -[UIViewController _setViewAppearState:isAnimating:] + 138
33 UIKit 0x30fff8a8 -[UIViewController beginAppearanceTransition:animated:] + 184
34 UIKit 0x310468be -[UIWindowController transition:fromViewController:toViewController:target:didEndSelector:] + 4098
35 UIKit 0x31045360 -[UIViewController presentViewController:withTransition:completion:] + 3116
36 UIKit 0x310a06a0 -[UIViewController presentModalViewController:animated:] + 24
37 CoreFoundation 0x371e93f6 -[NSObject performSelector:withObject:withObject:] + 46
38 UIKit 0x30f7ee00 -[UIApplication sendAction:to:from:forEvent:] + 56
39 UIKit 0x30f7edbc -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 24
40 UIKit 0x30f7ed9a -[UIControl sendAction:to:forEvent:] + 38
41 UIKit 0x30f7eb0a -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 486
42 UIKit 0x30f7f442 -[UIControl touchesEnded:withEvent:] + 470
43 UIKit 0x30f7d924 -[UIWindow _sendTouchesForEvent:] + 312
44 UIKit 0x30f7d312 -[UIWindow sendEvent:] + 374
45 UIKit 0x30f6368e -[UIApplication sendEvent:] + 350
46 UIKit 0x30f62f34 _UIApplicationHandleEvent + 5820
47 GraphicsServices 0x339a5224 PurpleEventCallback + 876
48 CoreFoundation 0x3726351c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 32
49 CoreFoundation 0x372634be __CFRunLoopDoSource1 + 134
50 CoreFoundation 0x3726230c __CFRunLoopRun + 1364
51 CoreFoundation 0x371e549e CFRunLoopRunSpecific + 294
52 CoreFoundation 0x371e5366 CFRunLoopRunInMode + 98
53 GraphicsServices 0x339a4432 GSEventRunModal + 130
54 UIKit 0x30f91cce UIApplicationMain + 1074
55 zApp 0x0007ffa6 0x79000 + 28582
56 zApp 0x0007a680 0x79000 + 5760
If you suspect that you are overreleasing something, try running your app with NSZombie enabled. (how to enable NSZombie)
You can set exception breakpoint to print backtrace in console.
sometimes that happens when you set an object as an observer for notifications, like
[[NSNotificationCenter defaultCenter] addObserver //details
and don't remove it from the observers list when it's released.
the system tries to send a message to it, and the app crashes because it's not there.
try adding
[[NSNotificationCenter defaultCenter] removeObserver:self];
in the dealloc function.
(even if you're working with arc, create a dealloc function, and write that in it).
good luck
来源：https://stackoverflow.com/questions/10895871/ios-objc-msgsend-crash-with-no-report-or-warning-given