我在Mac App Store上有一个应用程序，我收到了用户的这些崩溃报告，我无法重现或弄清楚如何调试。由于NSManagedObjectContext重置似乎崩溃了，但它并不明显，并且用户没有可重现的案例。主线程可以具有不同的堆栈跟踪，但非主线程始终具有相同的堆栈跟踪。
Exception Type: SIGSEGV
Exception Codes: SEGV_MAPERR at 0x41bfc026bec0
Crashed Thread: 8
Application Specific Information:
Selector name found in current argument registers: retain
Thread 0:
0 libFontParser.dylib 0x00007fff8efa7921 _ZNK20TTrueTypeFontHandler11RenderGlyphEtR27TTrueTypeQuadOutlineContextj + 89
1 libFontParser.dylib 0x00007fff8efa789e _ZNK20TTrueTypeFontHandler14GetOutlinePathEtRK18TGlyphOutlineBatch + 60
2 libFontParser.dylib 0x00007fff8efa744a FPFontCopyGlyphPath + 394
3 CoreGraphics 0x00007fff8767e913 CGFontCreateGlyphPath + 44
4 CoreGraphics 0x00007fff8767e85d CGFontCreateGlyphBitmap + 437
5 CoreGraphics 0x00007fff8767e607 _ZN14CGGlyphBuilder22create_missing_bitmapsEPK17CGGlyphIdentifiermPPK13CGGlyphBitmap + 109
6 libRIP.A.dylib 0x00007fff8b7bec2d render_glyphs + 204
7 libRIP.A.dylib 0x00007fff8b7bdf6f draw_glyph_bitmaps + 1585
8 libRIP.A.dylib 0x00007fff8b7bd8cd ripc_DrawGlyphs + 2785
9 CoreGraphics 0x00007fff87738077 draw_glyphs + 1034
10 CoreText 0x00007fff8ac50426 _ZL25DrawSbixGlyphsAtPositionsPK5TFontP6CGFontRK6TCFRefIPK8__CFDataEPKtPK7CGPointmP9CGContext17CGAffineTransformSI_ + 2990
11 CoreText 0x00007fff8abfdb73 CTFontDrawGlyphsWithAdvances + 789
12 UIFoundation 0x00007fff966f212e -[NSLineFragmentRenderingContext drawAtPoint:inContext:] + 5398
13 UIFoundation 0x00007fff96616728 __NSStringDrawingEngine + 16941
14 UIFoundation 0x00007fff966108ff _NSStringDrawingCore + 150
15 AppKit 0x00007fff93ce6d50 _NSDrawTextCell + 6954
16 AppKit 0x00007fff9421cdf8 __47-[NSTextFieldCell drawLayer:inGraphicsContext:]_block_invoke + 576
17 AppKit 0x00007fff944aa538 +[NSAppearance _performWithCurrentAppearance:usingBlock:] + 79
18 AppKit 0x00007fff93cf6739 -[NSTextFieldCell drawLayer:inGraphicsContext:] + 225
19 AppKit 0x00007fff93cf6470 +[NSGraphicsContext configureGraphicsContextForCALayer:withCGContext:andRenderWithHandler:] + 97
20 QuartzCore 0x00007fff939f1e93 CABackingStoreUpdate_ + 3306
21 QuartzCore 0x00007fff939f11a3 ___ZN2CA5Layer8display_Ev_block_invoke + 59
22 QuartzCore 0x00007fff939f115f x_blame_allocations + 81
23 QuartzCore 0x00007fff939f0c5c _ZN2CA5Layer8display_Ev + 1546
24 AppKit 0x00007fff93ce039f _NSBackingLayerDisplay + 617
25 QuartzCore 0x00007fff939f0381 _ZN2CA5Layer17display_if_neededEPNS_11TransactionE + 603
26 QuartzCore 0x00007fff939efabd _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 35
27 QuartzCore 0x00007fff939ef24e _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 242
28 QuartzCore 0x00007fff939eeea4 _ZN2CA11Transaction6commitEv + 390
29 QuartzCore 0x00007fff939ffcad _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 71
30 CoreFoundation 0x00007fff8bbd0da7 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
31 CoreFoundation 0x00007fff8bbd0d00 __CFRunLoopDoObservers + 368
32 CoreFoundation 0x00007fff8bbc2878 CFRunLoopRunSpecific + 328
33 HIToolbox 0x00007fff918f1aef RunCurrentEventLoopInMode + 235
34 HIToolbox 0x00007fff918f176e ReceiveNextEventCommon + 179
35 HIToolbox 0x00007fff918f16ab _BlockUntilNextEventMatchingListInModeWithFilter + 71
36 AppKit 0x00007fff93bb0f81 _DPSNextEvent + 964
37 AppKit 0x00007fff93bb0730 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 194
38 AppKit 0x00007fff93ba4593 -[NSApplication run] + 594
39 AppKit 0x00007fff93b8fa14 NSApplicationMain + 1832
40 libdyld.dylib 0x00007fff88d605c9 start + 1
...
Thread 7:
0 libsystem_kernel.dylib 0x00007fff94d1b94a __workq_kernreturn + 10
1 libsystem_pthread.dylib 0x00007fff9508740d start_wqthread + 13
Thread 8 Crashed:
0 libobjc.A.dylib 0x00007fff90c740dd objc_msgSend + 29
1 Foundation 0x00007fff92461d24 NSKeyValuePushPendingNotificationPerThread + 446
2 Foundation 0x00007fff9240968f NSKeyValueWillChange + 465
3 Foundation 0x00007fff924bc33e -[NSObject(NSKeyValueObservingPrivate) _willChangeValuesForKeys:] + 234
4 CoreData 0x00007fff8d9fdd6d -[NSFaultHandler turnObject:intoFaultWithContext:] + 221
5 CoreData 0x00007fff8da28641 -[NSManagedObjectContext(_NSInternalAdditions) _disposeObjects:count:notifyParent:] + 353
6 CoreData 0x00007fff8da27c78 -[NSManagedObjectContext(_NSInternalAdditions) _dispose:] + 392
7 CoreData 0x00007fff8da27821 -[NSManagedObjectContext _dealloc__] + 337
8 CoreData 0x00007fff8da563ab __internalBlockToDeallocNSManagedObjectContext_block_invoke + 75
9 CoreData 0x00007fff8da1c246 developerSubmittedBlockToNSManagedObjectContextPerform + 182
10 libdispatch.dylib 0x00007fff8f122c13 _dispatch_client_callout + 8
11 libdispatch.dylib 0x00007fff8f126365 _dispatch_queue_drain + 1100
12 libdispatch.dylib 0x00007fff8f127ecc _dispatch_queue_invoke + 202
13 libdispatch.dylib 0x00007fff8f1256b7 _dispatch_root_queue_drain + 463
14 libdispatch.dylib 0x00007fff8f133fe4 _dispatch_worker_thread3 + 91
15 libsystem_pthread.dylib 0x00007fff95089637 _pthread_wqthread + 729
16 libsystem_pthread.dylib 0x00007fff9508740d start_wqthread + 13
知道如何找出造成问题的原因并可能解决问题吗？我尝试过启用僵尸，将NSBindingDebugLogLevel设置为1，然后运行Zombies乐器，但没有运气。