Core data crash when resetting the store: 'Object's persistent store is not reachable from this NSManagedObjectContext's coordinator'

Question

I get a crash when trying to delete the persistent store of Core data in my iOS app written in Swift. The flow is straight forward: When I log out from the app I delete the store with:

destroyPersistentStoreAtURL

I use native Core Data implementation in the application and every access to a managed object is made with performBlock/performBlockAndWait. Also, these operations are in a NSOperationQueue. The flow is the following:

1. Log out
2. cancelAllOperations & waitUntilAllOperationsAreFinished on the queue that the performBlocks are implemented
3. maxConcurrentOperationCount = 1 on the queue of the performBlocks
4. Finally, I add an operation which destroys the persistent store in the previous NSOperationQueue

Sometimes, I get a crash and I cannot understand why. From what I see, it is something related with managedObjectsIDs and retain. Take a look:

2016-11-14 15:51:58.053 ******[3912:179074] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Object's persistent store is not reachable from this NSManagedObjectContext's coordinator'
*** First throw call stack:
(
	0   CoreFoundation                      0x000000010ca0f34b __exceptionPreprocess + 171
	1   libobjc.A.dylib                     0x000000010c05321e objc_exception_throw + 48
	2   CoreData                            0x000000010c5683b2 _PFRetainedObjectIDCore + 1074
	3   CoreData                            0x000000010c5507fc -[NSManagedObjectContext objectWithID:] + 668
	4   CoreData                            0x000000010c590264 _faultBatchAtIndex + 1524
	5   CoreData                            0x000000010c59217a -[_PFBatchFaultingArray retainedObjectAtIndex:] + 74
	6   CoreData                            0x000000010c592262 -[_PFBatchFaultingArray objectAtIndex:] + 50
	7   CoreData                            0x000000010c67d9de __72-[NSFetchedResultsController(PrivateMethods) _computeSectionInfo:error:]_block_invoke + 190
	8   CoreData                            0x000000010c55adc7 developerSubmittedBlockToNSManagedObjectContextPerform + 199
	9   CoreData                            0x000000010c55ac7f -[NSManagedObjectContext performBlockAndWait:] + 255
	10  CoreData                            0x000000010c67d3b6 -[NSFetchedResultsController(PrivateMethods) _computeSectionInfo:error:] + 694
	11  CoreData                            0x000000010c681d75 __82-[NSFetchedResultsController(PrivateMethods) _core_managedObjectContextDidChange:]_block_invoke + 1077
	12  CoreData                            0x000000010c55adc7 developerSubmittedBlockToNSManagedObjectContextPerform + 199
	13  CoreData                            0x000000010c55ac7f -[NSManagedObjectContext performBlockAndWait:] + 255
	14  CoreData                            0x000000010c681927 -[NSFetchedResultsController(PrivateMethods) _core_managedObjectContextDidChange:] + 119
	15  CoreFoundation                      0x000000010c9ad19c __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 12
	16  CoreFoundation                      0x000000010c9ad09b _CFXRegistrationPost + 427
	17  CoreFoundation                      0x000000010c9ace02 ___CFXNotificationPost_block_invoke + 50
	18  CoreFoundation                      0x000000010c96fea2 -[_CFXNotificationRegistrar find:object:observer:enumerator:] + 2018
	19  CoreFoundation                      0x000000010c96ef3b _CFXNotificationPost + 667
	20  Foundation                          0x000000010bb1b0ab -[NSNotificationCenter postNotificationName:object:userInfo:] + 66
	21  CoreData                            0x000000010c5432b0 -[NSManagedObjectContext(_NSInternalNotificationHandling) _postObjectsDidChangeNotificationWithUserInfo:] + 704
	22  CoreData                            0x000000010c562b50 -[NSManagedObjectContext(_NSInternalNotificationHandling) _processChangedStoreConfigurationNotification:] + 2976
	23  CoreData                            0x000000010c5d97ed __95-[NSManagedObjectContext(_NSInternalNotificationHandling) _sendOrEnqueueNotification:selector:]_block_invoke + 109
	24  CoreData                            0x000000010c55adc7 developerSubmittedBlockToNSManagedObjectContextPerform + 199
	25  libdispatch.dylib                   0x000000010e0250cd _dispatch_client_callout + 8
	26  libdispatch.dylib                   0x000000010e0058d6 _dispatch_main_queue_callback_4CF + 406
	27  CoreFoundation                      0x000000010c9d34f9 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
	28  CoreFoundation                      0x000000010c998f8d __CFRunLoopRun + 2205
	29  CoreFoundation                      0x000000010c998494 CFRunLoopRunSpecific + 420
	30  GraphicsServices                    0x000000010f5d0a6f GSEventRunModal + 161
	31  UIKit                               0x000000010a050964 UIApplicationMain + 159
	32  ******                              0x000000010817e932 main + 114
	33  libdyld.dylib                       0x000000010e07168d start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException

Any help is much appreciated!

Answer 1

You need to reset managedObjectContext which was used before this operation.

Call managedObjectContext.reset()