应用特定信息：
* 由于未捕获的异常“NSGenericException”而终止应用程序，原因：“* Collection <__NSCFArray: 0x1f03a140> 在枚举时发生了变异。”
Application Specific Backtrace 1:
0 CoreFoundation 0x329a83e7 -[NSException encodeWithCoder:] + 218
1 libobjc.A.dylib 0x3a6a3963 +[Protocol load] + 22070
2 CoreFoundation 0x329a7ec1 -[NSException name] + 0
3 Foundation 0x33361e0f -[NSISLinearExpression enumerateVariables:] + 118
4 Foundation 0x33359a5b -[NSISEngine removeRowWithHead:] + 142
5 Foundation 0x3335a61f -[NSISEngine pivotToMakeBodyVar:newHeadOfRowWithHead:] + 174
6 Foundation 0x3335e891 -[NSISEngine removeConstraintWithMarker:] + 280
7 Foundation 0x33366eab -[NSLayoutConstraint _removeFromEngine:] + 230
8 UIKit 0x34bf6bcd -[UIView _removeRelevantConstraintsFromEngine:] + 408
9 Foundation 0x3335d997 -[NSISEngine withAutomaticOptimizationDisabled:] + 166
10 UIKit 0x34bf6a95 -[UIView _removeRelevantConstraintsFromEngine:] + 96
11 UIKit 0x3499ce55 -[UIView _willRemoveSubviewWantingAutolayout:] + 840
12 UIKit 0x347e58d5 -[UIView removeFromSuperview] + 56
13 UIKit 0x34835f41 -[UINavigationTransitionView _cleanupTransition] + 92
14 UIKit 0x347ccabb -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] + 158
15 UIKit 0x348418fd -[UIViewAnimationState animationDidStop:finished:] + 48
16 QuartzCore 0x34578309 -[CALayer dealloc] + 1240
17 libdispatch.dylib 0x3aabd5db 0x3aabc000 + 5595
18 libdispatch.dylib 0x3aac0e45 -[OS_object _dispose] + 11552
19 CoreFoundation 0x3297c1b1 +[__NSCFLocale automaticallyNotifiesObserversForKey:] + 12368
20 CoreFoundation 0x328ef23d -[__NSDate timeIntervalSinceReferenceDate] + 500
21 CoreFoundation 0x328ef0c9 -[__NSDate timeIntervalSinceReferenceDate] + 128
22 GraphicsServices 0x364ce33b 0x364c9000 + 21307
23 UIKit 0x3480b2b9 +[UIImage kitImageNamed:] + 1128
24 MyApplication 0x0009c78b -[Reachability currentReachabilityStatus] + 226
25 libdyld.dylib 0x3aad0b20 0x3aacf000 + 6944
我已经在我的应用程序的很多位置使用了可达性 API，但是通过这个堆栈跟踪，我似乎无法弄清楚错误发生在哪里！
有人可以指出我正确的方向吗？