CODEWITHSUNDEEP
iosobjective-cxcode
user3724714
user3724714

Reputation: 31

Terminating app due to uncaught exception 'NSGenericException', reason: '*** Collection <__NSSetM...> was mutated while being enumerated.'

I don't understand problem, but I guess the problem in storyboard (In my constraints, because sometimes objects isn't where they must be).

* Terminating app due to uncaught exception 'NSGenericException', reason: '* 

Collection <__NSSetM: 0x7fae0b5e6900> was mutated while being enumerated.'
*** First throw call stack:

 - (
    0   CoreFoundation   __exceptionPreprocess + 165

    1   libobjc.A.dylib  objc_exception_throw + 45

    2   CoreFoundation __NSFastEnumerationMutationHandler + 132

    3   Foundation  -[NSISEngine substituteOutAllOccurencesOfBodyVar:withExpression:] + 336

    4   Foundation -[NSISEngine pivotToMakeBodyVar:newHeadOfRowWithHead:andDropRow:] + 330

    5   Foundation   -[NSISEngine minimizeConstantInObjectiveRowWithHead:] + 314

    6   Foundation  -[NSISEngine tryUsingArtificialVariableToAddConstraintWithMarker:rowBody:usingInfeasibilityHandlingBehavior:mutuallyExclusiveConstraints:] + 285

    7   Foundation  -[NSISEngine tryToAddConstraintWithMarker:expression:integralizationAdjustment:mutuallyExclusiveConstraints:] + 691

    8   Foundation   -[NSLayoutConstraint _addLoweredExpression:toEngine:integralizationAdjustment:lastLoweredConstantWasRounded:mutuallyExclusiveConstraints:] + 275

    9   Foundation   -[NSLayoutConstraint _addToEngine:integralizationAdjustment:mutuallyExclusiveConstraints:] + 220

    10  UIKit  -[UIView(UIConstraintBasedLayout) _layoutEngine_didAddLayoutConstraint:roundingAdjustment:mutuallyExclusiveConstraints:] + 411

    11  UIKit -[UIView(UIConstraintBasedLayout) _tryToAddConstraintWithoutUpdatingConstraintsArray:roundingAdjustment:mutuallyExclusiveConstraints:] + 30

    12  UIKit [UIView(UIConstraintBasedLayout) _tryToAddConstraint:roundingAdjustment:mutuallyExclusiveConstraints:] + 243

    13  UIKit -[UIView(UIConstraintBasedLayout) addConstraints:]_block_invoke + 188

    14  Foundation [NSISEngine withBehaviors:performModifications:] + 155

    15  UIKit  [UIView(UIConstraintBasedLayout) addConstraints:] + 263

    16  UIKit-[UIView _setTraitStorageConstraints:] + 794

Upvotes: 2

Views: 5364

Answers (2)

leavez
leavez

Reputation: 2218

Maybe some other background thread and main thread call autolayout functions simultaneously. Check out other threads in the crash log.

Upvotes: 1

danialzahid94
danialzahid94

Reputation: 4223

This isn't a problem with auto layouts. You are using an Array or Dictionary or some NSSet object which is being mutated (values are being added to it) while being enumerated (values are being read form it).

This problem mainly arises when you populate something like an Array and then reload a UITableView or UICollectionView

Upvotes: 2

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