I'm looking for guidance how to mitigate this crash. It seems super deep inside Core Data' FRC fetchedObjects management. In my code, it's initiated by this viewContext.perform { [unowned self] in self.viewContext.mergeChanges(fromContextDidSave: notification) } which is directly followed by the stack trace below. Basically merging data from .NSManagedObjectContextDidSave notification from another NSManagedObjectContext. Nothing special, it works great for years, apart from these rare occurrences. Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Exception Reason: -[__NSCFArray objectAtIndex:]: index (235) beyond bounds (234) Termination Reason: SIGNAL 6 Abort trap: 6 Triggered by Thread: 0 Last Exception Backtrace: 0 CoreFoundation 0x199e947cc __exceptionPreprocess + 164 (NSException.m:249) 1 libobjc.A.dylib 0x1971672e4 objc_exception_throw + 88 (objc-exception.mm:356) 2 CoreFoundation 0x199fc4258 _NSArrayRaiseBoundException + 368 (NSCFArray.m:22) 3 CoreFoundation 0x199e288a4 -[__NSCFArray objectAtIndex:] + 200 (NSCFArray.m:42) 4 CoreData 0x1a1e17338 -[_PFMutableProxyArray objectAtIndex:] + 40 (_PFArray.m:1860) 5 CoreData 0x1a1e1673c -[NSFetchedResultsController _updateFetchedObjectsWithInsertChange:] + 380 (NSFetchedResultsController.m:1582) 6 CoreData 0x1a1e1426c __82-[NSFetchedResultsController(PrivateMethods) _core_managedObjectContextDidChange:]_block_invoke + 2240 (NSFetchedResultsController.m:2171) 7 CoreData 0x1a1dcdf80 developerSubmittedBlockToNSManagedObjectContextPerform + 156 (NSManagedObjectContext.m:4002) 8 CoreData 0x1a1e41a44 -[NSManagedObjectContext performBlockAndWait:] + 216 (NSManagedObjectContext.m:4113) 9 CoreData 0x1a1e41034 -[NSFetchedResultsController _core_managedObjectContextDidChange:] + 124 (NSFetchedResultsController.m:2379) 10 CoreFoundation 0x199e632f4 __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148 (CFNotificationCenter.c:701) 11 CoreFoundation 0x199e63210 ___CFXRegistrationPost_block_invoke + 88 (CFNotificationCenter.c:194) 12 CoreFoundation 0x199e63158 _CFXRegistrationPost + 436 (CFNotificationCenter.c:222) 13 CoreFoundation 0x199e6170c _CFXNotificationPost + 728 (CFNotificationCenter.c:1248) 14 Foundation 0x198a84ea4 -[NSNotificationCenter postNotificationName:object:userInfo:] + 92 (NSNotification.m:531) 15 CoreData 0x1a1e11650 -[NSManagedObjectContext _createAndPostChangeNotification:deletions:updates:refreshes:deferrals:wasMerge:] + 1736 (NSManagedObjectContext.m:8098) 16 CoreData 0x1a1e10e0c -[NSManagedObjectContext _postRefreshedObjectsNotificationAndClearList] + 164 (NSManagedObjectContext.m:7631) 17 CoreData 0x1a1e0fad8 -[NSManagedObjectContext _processRecentChanges:] + 100 (NSManagedObjectContext.m:7714) 18 CoreData 0x1a1e3563c -[NSManagedObjectContext _coreMergeChangesFromDidSaveDictionary:usingObjectIDs:withClientQueryGeneration:] + 3436 (NSManagedObjectContext.m:3723) 19 CoreData 0x1a1e34350 __116+[NSManagedObjectContext(_NSCoreDataSPI) _mergeChangesFromRemoteContextSave:intoContexts:withClientQueryGeneration:]_block_invoke_4 + 76 (NSManagedObjectContext.m:9531) 20 CoreData 0x1a1dcdf80 developerSubmittedBlockToNSManagedObjectContextPerform + 156 (NSManagedObjectContext.m:4002) 21 CoreData 0x1a1e41a44 -[NSManagedObjectContext performBlockAndWait:] + 216 (NSManagedObjectContext.m:4113) 22 CoreData 0x1a1e39880 +[NSManagedObjectContext _mergeChangesFromRemoteContextSave:intoContexts:withClientQueryGeneration:] + 2372 (NSManagedObjectContext.m:9537) 23 CoreData 0x1a1e344a0 -[NSManagedObjectContext mergeChangesFromContextDidSaveNotification:] + 292 (NSManagedObjectContext.m:0)

I get this error, i have my own DIKit, and i want to use swiftdata for showing info from persisten model. It works all over the app, but i get this error with my .sheet. // JobCreationView.swift // Features // // Created by Jens Vik on 26/03/2025. // import SwiftUI import DesignKit import DIKit import PresentationKit import CoreKit import DomainKit import SwiftData public struct JobCreationView: View { @Binding var isPresented: Bool // Inject view model using DIKit's property wrapper @Injected((any JobCreationViewModelProtocol).self) private var viewModel // Form state @Injected(ModelContext.self) private var modelContext @State private var date = Date() @State private var isASAP = false @State private var price = "" @State private var jobType = "Fiks" @State private var description = "" // Available job types private let jobTypes = ["Fiks", "Fiksit"] @Query private var userContexts: [UserContextModel] public init(isPresented: Binding<Bool>) { self._isPresented = isPresented print("DEBUG: JobCreationView initialized") } public var body: some View { let city = userContexts.first?.city ?? "Loading..." NavigationView { Form { Section(header: Text("Location")) { Text(city) } Section(header: Text("Details")) { TextField("Price", text: $price) .keyboardType(.numberPad) Picker("Job Type", selection: $jobType) { ForEach(jobTypes, id: \.self) { type in Text(type).tag(type) } } .pickerStyle(SegmentedPickerStyle()) TextEditor(text: $description) .frame(minHeight: 100) .overlay( RoundedRectangle(cornerRadius: 8) .stroke(Color.gray.opacity(0.2), lineWidth: 1) ) } } .navigationBarTitle("Create Job", displayMode: .inline) .navigationBarItems( leading: Button("Cancel") { isPresented = false }, trailing: Button("Post") { // Post functionality will be added later isPresented = false } .disabled( (!isASAP && date < Date()) || price.isEmpty || description.isEmpty) ) } } } How bad is this macro error? error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift"

Hi there, I got two models here: Two Models, with Many-To-Many Relationship @Model final class PresetParams: Identifiable { @Attribute(.unique) var id: UUID = UUID() var positionX: Float = 0.0 var positionY: Float = 0.0 var positionZ: Float = 0.0 var volume: Float = 1.0 @Relationship(deleteRule: .nullify, inverse: \Preset.presetAudioParams) var preset = [Preset]() init(position: SIMD3<Float>, volume: Float) { self.positionX = position.x self.positionY = position.y self.positionZ = position.z self.volume = volume self.preset = [] } var position: SIMD3<Float> { get { return SIMD3<Float>(x: positionX, y: positionY, z: positionZ) } set { positionX = newValue.x positionY = newValue.y positionZ = newValue.z } } } @Model final class Preset: Identifiable { @Attribute(.unique) var id: UUID = UUID() var presetName: String var presetDesc: String? var presetAudioParams = [PresetParams]() // Many-To-Many Relationship. init(presetName: String, presetDesc: String? = nil) { self.presetName = presetName self.presetDesc = presetDesc self.presetAudioParams = [] } } To be honest, I don't fully understand how the @Relationship thing works properly in a Many-To-Many relationship situation. Some tutorials suggest that it's required on the "One" side of an One-To-Many Relationship, while the "Many" side doesn't need it. And then there is an ObservableObject called "ModelActors" to manage all ModelActors, ModelContainer, etc. ModelActors, ModelContainer... class ModelActors: ObservableObject { static let shared: ModelActors = ModelActors() let sharedModelContainer: ModelContainer private init() { var schema = Schema([ // ... Preset.self, PresetParams.self, // ... ]) do { sharedModelContainer = try ModelContainer(for: schema, migrationPlan: MigrationPlan.self) } catch { fatalError("Could not create ModelContainer: \(error.localizedDescription)") } } } And there is a migrationPlan: MigrationPlan // MARK: V102 // typealias ... // MARK: V101 typealias Preset = AppSchemaV101.Preset typealias PresetParams = AppSchemaV101.PresetParams // MARK: V100 // typealias ... enum MigrationPlan: SchemaMigrationPlan { static var schemas: [VersionedSchema.Type] { [ AppSchemaV100.self, AppSchemaV101.self, AppSchemaV102.self, ] } static var stages: [MigrationStage] { [AppMigrateV100toV101, AppMigrateV101toV102] } static let AppMigrateV100toV101 = MigrationStage.lightweight(fromVersion: AppSchemaV100.self, toVersion: AppSchemaV101.self) static let AppMigrateV101toV102 = MigrationStage.lightweight(fromVersion: AppSchemaV101.self, toVersion: AppSchemaV102.self) } // MARK: Here is the AppSchemaV101 enum AppSchemaV101: VersionedSchema { static var versionIdentifier: Schema.Version = Schema.Version(1, 0, 1) static var models: [any PersistentModel.Type] { return [ // ... Preset.self, PresetParams.self ] } } Fails on iOS 18.3.x: "Failed to fulfill link PendingRelationshipLink" So I expected the SwiftData subsystem to work correctly with version control. A good news is that on iOS 18.1 it does work. But it fails on iOS 18.3.x with a fatal Error: "SwiftData/SchemaCoreData.swift:581: Fatal error: Failed to fulfill link PendingRelationshipLink(relationshipDescription: (<NSRelationshipDescription: 0x30377fe80>), name preset, isOptional 0, isTransient 0, entity PresetParams, renamingIdentifier preset, validation predicates (), warnings (), versionHashModifier (null)userInfo {}, destination entity Preset, inverseRelationship (null), minCount 0, maxCount 0, isOrdered 0, deleteRule 1, destinationEntityName: "Preset", inverseRelationshipName: Optional("presetAudioParams")), couldn't find inverse relationship 'Preset.presetAudioParams' in model" Fails on iOS 17.5: Another Error I tested it on iOS 17.5 and found another issue: Accessing or mutating the "PresetAudioParams" property causes the SwiftData Macro Codes to crash, affecting both Getter and Setter. It fails with an error: "EXC_BREAKPOINT (code=1, subcode=0x1cc1698ec)" Tweaking the @Relationship marker and ModelContainer settings didn't fix the problem.

Hi. I am having this error when trying to write to CloudKit public database. <CKError 0x600000dbc4e0: "Permission Failure" (10/2007); server message = "Invalid bundle ID for container"; On app launch, I check for account status and ensure that the correct bundle identifier and container is being used. When the account status is checked, I do get the correct bundle id and container id printed in the console but trying to read or write to the container would throw that "Invalid bundle ID for container" error. private init() { container = CKContainer.default() publicDB = container.publicCloudDatabase // Check iCloud account status checkAccountStatus() } func checkAccountStatus() { print("🔍 CloudKit Debug:") print("🔍 Bundle identifier from app: (Bundle.main.bundleIdentifier ?? "unknown")") print("🔍 Container identifier: (container.containerIdentifier ?? "unknown")") container.accountStatus { [weak self] status, error in DispatchQueue.main.async { switch status { case .available: self?.isSignedIn = true self?.fetchUserID() case .noAccount, .restricted, .couldNotDetermine: self?.isSignedIn = false self?.errorMessage = "Please sign in to iCloud in Settings to use this app." default: self?.isSignedIn = false self?.errorMessage = "Unknown iCloud account status." } print("User is signed into iCloud: \(self?.isSignedIn ?? false)") print("Account status: \(status.rawValue)") } } } I have tried: Creating a new container Unselecting and selecting the container in signing & capabilities Unselecting and selecting the container in App ID Configuration I used to have swift data models in my code and read that swift data is not compatible with CloudKit public data so I removed all the models and any swift data codes and only uses CloudKit public database. let savedRecord = try await publicDB.save(record) Nothing seems to work. If anyone could help please? Rgds, Hans

Setup I am running a versionedSchema for my SwiftData model and attempting a migration. The new version contains a new attribute, with a type of a new custom enum defined in the @Model class, a default value, and a private(set). Migration was completed with a migrationPlan with nil values for willMigrate and didMigrate. Example - Previous Version @Model class MyNumber { var num: Int init() { // Init Code } } Example - Newest Version @Model class MyNumber { var num: Int private(set) var rounding: RoundAmount = MyNumber.RoundAmount.thirtyMinute init() { // Init Code } enum RoundAmount { case fiveMinute, tenMinute, thirtyMinute } } Issue Running this code, I get a swiftData error for “SwiftData/ModelCoders.swift:1585: nil value passed for a non-optional keyPath, /MyNumber.rounding” I assume this means a failure of the swiftData lightweight migration? I have reverted the version, removed private(set) and re-tried the migration with no success. Using the versionedSchema with migrationPlans, are lightweight migrations possible? Could this be an issue with the use of a custom enum? Other changes in my actual project migrated successfully so I’m lost on why I’m having this issue.

Hi, I keep trying to use transformable to store an array of strings with SwiftData, and I can see that it is activating the transformer, but it keeps saying that I am still using NSArray instead of NSData. *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unacceptable type of value for attribute: property = "category"; desired type = NSData; given type = Swift.__SwiftDeferredNSArray; value = ( yo, gurt ).' terminating due to uncaught exception of type NSException CoreSimulator 1010.10 - Device: iPhone 16 18.0 (6879535B-3174-4025-AD37-ED06E60291AD) - Runtime: iOS 18.0 (22A3351) - DeviceType: iPhone 16 Message from debugger: killed @Model class MyModel: Identifiable, Equatable { @Attribute(.transformable(by: StringArrayTransformer.self)) var category: [String]? @Attribute(.transformable(by: StringArrayTransformer.self)) var amenities: [String]? var image: String? var parentChunck: MyModelDataChunk_V1? init(category: [String]?, amenities: [String]?) { self.category = category self.amenities = amenities } } class StringArrayTransformer: ValueTransformer { override func transformedValue(_ value: Any?) -> Any? { print(value) guard let array = value as? [String] else { return nil } let data = try? JSONSerialization.data(withJSONObject: array, options: []) print(data) return data } override func reverseTransformedValue(_ value: Any?) -> Any? { guard let data = value as? Data else { return nil } let string = (try? JSONSerialization.jsonObject(with: data, options: [])) as? [String] print(string) return string } override class func transformedValueClass() -> AnyClass { return NSData.self } override class func allowsReverseTransformation() -> Bool { return true } static func register() { print("regitsering") ValueTransformer.setValueTransformer(StringArrayTransformer(), forName: .stringArrayTransformerName) } } extension NSValueTransformerName { static let stringArrayTransformerName = NSValueTransformerName("StringArrayTransformer") }

I am working with SwiftData and get the below error. I can't find any documentation on it to see what to fix. Any help would be appreciated. Fatal error: This relationship already has a value but it's not the target:

There's some logic in my app that first checks to see if a specific CloudKit record zone exists. If it doesn't, it creates the zone, and then my application continues on with its work. The way I've implemented this right now is by catching the zoneNotFound error when I call CKDatabase#recordZone(for:) (docs) and creating the zone when that happens: do { try await db.recordZone(for: zoneID) } catch let ckError as CKError where [.zoneNotFound, .userDeletedZone].contains(ckError.code) { // createZone is a helper function try await createZone(zoneID: zoneID, context: context) } This works great, but every time I do this, an error is logged in CloudKit Console, which creates a lot of noise and makes it harder to see real errors. Is there a way to do this without explicitly triggering a CloudKit error? I just found CKDatabase#recordZones(for:) (docs), which seems like it returns an empty array instead of throwing an error if the zone doesn't exist. Will calling that and looking for a non-empty array work just as well, but without logging lots of errors in the console?

Hi, I am testing a situation with shared CKRecords where the data in the CKRecord syncs fine, but the creatorUserRecordID.recordName and lastModifiedUserRecordID.recordName shows "defaultOwner" (which maps to the CKCurrentUserDefaultName constant) even though I made sure I edit the CKRecord value from a different iCloud account. In fact, on the CloudKit dashboard, it shows the correct user recordIDs in the metadata for the 'Created' and 'Modified' fields, but not in the CKRecord. I am mostly testing this on the iPhone simulator with the debugger attached. Is that a possible reason for this, or is there some other reason the lastModifiedUserRecordID is showing the value for 'CKCurrentUserDefaultName'? It would be pretty difficult to build in functionality to look up changes by a different userID if this is the case.

The following complex migration consistently crashes the app with the following error: SwiftData/PersistentModel.swift:726: Fatal error: What kind of backing data is this? SwiftData._KKMDBackingData<SwiftDataMigration.ItemSchemaV1.ItemList> My app relies on a complex migration that involves these optional 1 to n relationships. Theoretically I could not assign the relationships in the willMigrate block but afterwards I am not able to tell which list and items belonged together. Steps to reproduce: Run project Change typealias CurrentSchema to ItemSchemaV2 instead of ItemSchemaV1. Run project again -> App crashes My setup: Xcode Version 16.2 (16C5032a) MacOS Sequoia 15.4 iPhone 12 with 18.3.2 (22D82) Am I doing something wrong or did I stumble upon a bug? I have a demo Xcode project ready but I could not upload it here so I put the code below. Thanks for your help typealias CurrentSchema = ItemSchemaV1 typealias ItemList = CurrentSchema.ItemList typealias Item = CurrentSchema.Item @main struct SwiftDataMigrationApp: App { var sharedModelContainer: ModelContainer = { do { return try ModelContainer(for: ItemList.self, migrationPlan: MigrationPlan.self) } catch { fatalError("Could not create ModelContainer: \(error)") } }() var body: some Scene { WindowGroup { ContentView() } .modelContainer(sharedModelContainer) } } This is the migration plan enum MigrationPlan: SchemaMigrationPlan { static var schemas: [any VersionedSchema.Type] { [ItemSchemaV1.self, ItemSchemaV2.self] } static var stages: [MigrationStage] = [ MigrationStage.custom(fromVersion: ItemSchemaV1.self, toVersion: ItemSchemaV2.self, willMigrate: { context in print("Started migration") let oldlistItems = try context.fetch(FetchDescriptor<ItemSchemaV1.ItemList>()) for list in oldlistItems { let items = list.items.map { ItemSchemaV2.Item(timestamp: $0.timestamp)} let newList = ItemSchemaV2.ItemList(items: items, name: list.name, note: "This is a new property") context.insert(newList) context.delete(list) } try context.save() // Crash indicated here print("Finished willMigrate") }, didMigrate: { context in print("Did migrate successfully") }) ] } The versioned schemas enum ItemSchemaV1: VersionedSchema { static var versionIdentifier = Schema.Version(1, 0, 0) static var models: [any PersistentModel.Type] { [Item.self] } @Model final class Item { var timestamp: Date var list: ItemSchemaV1.ItemList? init(timestamp: Date) { self.timestamp = timestamp } } @Model final class ItemList { @Relationship(deleteRule: .cascade, inverse: \ItemSchemaV1.Item.list) var items: [Item] var name: String init(items: [Item], name: String) { self.items = items self.name = name } } } enum ItemSchemaV2: VersionedSchema { static var versionIdentifier = Schema.Version(2, 0, 0) static var models: [any PersistentModel.Type] { [Item.self] } @Model final class Item { var timestamp: Date var list: ItemSchemaV2.ItemList? init(timestamp: Date) { self.timestamp = timestamp } } @Model final class ItemList { @Relationship(deleteRule: .cascade, inverse: \ItemSchemaV2.Item.list) var items: [Item] var name: String var note: String init(items: [Item], name: String, note: String = "") { self.items = items self.name = name self.note = note } } } Last the ContentView: struct ContentView: View { @Query private var itemLists: [ItemList] var body: some View { NavigationSplitView { List { ForEach(itemLists) { list in NavigationLink { List(list.items) { item in Text(item.timestamp.formatted(date: .abbreviated, time: .complete)) } .navigationTitle(list.name) } label: { Text(list.name) } } } .navigationTitle("Crashing migration demo") .onAppear { if itemLists.isEmpty { for index in 0..<10 { let items = [Item(timestamp: Date.now)] let listItem = ItemList(items: items, name: "List No. \(index)") modelContext.insert(listItem) } try! modelContext.save() } } } detail: { Text("Select an item") } } }

Hello, In our app, we’ve modeled our schema using inheritance introduced in iOS 26.0, and we’re implementing SwiftData History to re-fetch models only when necessary. @Model public class Transaction { @Attribute(.preserveValueOnDeletion) public var date: Date = Date() public var amount: Double = 0 public var memo: String? } @Model public final class Spending: Transaction { public var installmentIndex: Int = 1 public var installment: Int = 1 public var installmentID: UUID? } If data has been deleted from database, we need to check a date property to determine whether to re-fetch datas. To do this, we added the preserveValueOnDeletion attribute to date property so we could retrieve it from the History tombstone value. However, after adding this attribute, a crash occurs. There is a console log Could not cast value of type 'Swift.ReferenceWritableKeyPath<Shared.ModelSchemaV5.Transaction, Foundation.Date>' (0x106bf8328) to 'Swift.PartialKeyPath<Shared.ModelSchemaV5.Spending>' (0x1094f21d8). and error log attached StrictMoneyChecking-2025-11-07-105108.txt I also tried this in the recent SampleTrip app, and fetching all history after a deletion causes the same crash. Is this issue currently being worked on or under investigation?

CloudKit CKRecordZone Deletion Issue Problem: CloudKit record zones deleted via CKDatabase.modifyRecordZones(deleting:) or CKModifyRecordZonesOperation are successfully removed but then reappear. I suspect they are automatically reinstated by CloudKit sync, despite successful deletion confirmation. Environment: SwiftData with CloudKit integration Custom CloudKit zones created for legacy zone-based sharing Observed Behavior: Create custom zone (e.g., "TestZone1") via CKDatabase.modifyRecordZones(saving:) Copy records to zone for sharing purposes Delete zone using any CloudKit deletion API - returns success, no errors Immediate verification: Zone is gone from database.allRecordZones() After SwiftData/CloudKit sync or app restart: Zone reappears Reproduction: Tested with three different deletion methods - all exhibit same behaviour: modifyRecordZones(deleting:) async API CKModifyRecordZonesOperation (fire-and-forget) CKModifyRecordZonesOperation with result callbacks Zone deletion succeeds, change tokens (used to track updates to shared records) cleaned up But zones are restored presumably by CloudKit background sync Expected: Deleted zones should remain deleted Actual: Zones are reinstated, creating orphaned zones

I'm experiencing a critical issue with SwiftData custom migrations where objects created during migration appear to be inserted successfully but aren't persisted or found by queries after migration completes. The migration logs show objects being created, but subsequent queries return zero results. I'm migrating from schema version V2 to V2_5, which involves: Renaming Person class to GroupData Keeping the same data structure but changing the class name while keeping the old class. Using a custom migration stage to copy data from old to new schema Below is an extract of my two schema and migration plan: Environment: Xcode 16.0, iOS 18.0, Swift 6.0 SchemaV2 enum LinkMapV2: VersionedSchema { static let versionIdentifier: Schema.Version = .init(2, 0, 0) static var models: [any PersistentModel.Type] { [AnnotationData.self, Person.self, History.self] } @Model final class Person { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var statue: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.statue = status self.annotationId = annotationId self.number = number } } } Schema V2_5 static let versionIdentifier: Schema.Version = .init(2, 5, 0) static var models: [any PersistentModel.Type] { [AnnotationData.self, Person.self, GroupData.self, History.self] } // Keep the old Person model for migration @Model final class Person { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var statue: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.statue = status self.annotationId = annotationId self.number = number } } // Add the new GroupData model that mirrors Person @Model final class GroupData { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var status: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.status = status self.annotationId = annotationId self.number = number } } } Migration Plan static let migrationV2toV2_5 = MigrationStage.custom( fromVersion: LinkMapV2.self, toVersion: LinkMapV2_5.self, willMigrate: { context in do { let persons = try context.fetch(FetchDescriptor<LinkMapV2.Person>()) print("=== MIGRATION STARTED ===") print("Found \(persons.count) Person objects to migrate") guard !persons.isEmpty else { print("No Person data requires migration") return } for person in persons { print("Migrating Person: '\(person.name)' with ID: \(person.id)") let newGroup = LinkMapV2_5.GroupData( id: person.id, // Keep the same ID name: person.name, photo: person.photo, requirement: person.requirement, status: person.statue, annotationId: person.annotationId, number: person.number ) context.insert(newGroup) print("Inserted new GroupData: '\(newGroup.name)'") // Don't delete the old Person yet to avoid issues // context.delete(person) } try context.save() print("=== MIGRATION COMPLETED ===") print("Successfully migrated \(persons.count) Person objects to GroupData") } catch { print("=== MIGRATION ERROR ===") print("Migration failed with error: \(error)") } }, didMigrate: { context in do { // Verify migration in didMigrate phase let groups = try context.fetch(FetchDescriptor<LinkMapV2_5.GroupData>()) let oldPersons = try context.fetch(FetchDescriptor<LinkMapV2_5.Person>()) print("=== MIGRATION VERIFICATION ===") print("New GroupData count: \(groups.count)") print("Remaining Person count: \(oldPersons.count)") // Now delete the old Person objects for person in oldPersons { context.delete(person) } if !oldPersons.isEmpty { try context.save() print("Cleaned up \(oldPersons.count) old Person objects") } // Print all migrated groups for debugging for group in groups { print("Migrated Group: '\(group.name)', Status: \(group.status), Number: \(group.number)") } } catch { print("Migration verification error: \(error)") } } ) And I've attached console output below: Console Output

If Cloudkit is enabled, SwiftData @Query operation hangs when the View scenePhase becomes active. Seems like the more @Query calls you have, the more it hangs. This has been first documented some time ago, but in typical Apple style, it has not been addressed or even commented on. https://developer.apple.com/forums/thread/761434

I'm working on a new app with SwiftData and now adding CloudKit Sync. Everything is working fine in the simulator against the development CloudKit Schema. I successfully deployed the schema to production. However, the TestFlight builds fail against production. This is what I see in the logs, but I haven't been able to find info on how to fix it. Help appreciated. CoreData+CloudKit: -[NSCloudKitMirroringDelegate _requestAbortedNotInitialized:](2205): <private> - Never successfully initialized and cannot execute request '<private>' due to error: Error Domain=CKErrorDomain Code=2 "CKInternalErrorDomain: 1011" UserInfo={ContainerID=<private>, NSDebugDescription=CKInternalErrorDomain: 1011, CKPartialErrors=<private>, RequestUUID=<private>, NSLocalizedDescription=<private>, CKErrorDescription=<private>, NSUnderlyingError=0x1078e9fe0 {Error Domain=CKInternalErrorDomain Code=1011 UserInfo={CKErrorDescription=<private>, NSLocalizedDescription=<private>, CKPartialErrors=<private>}}} CoreData+CloudKit: -[NSCloudKitMirroringDelegate _performSetupRequest:]_block_invoke(1153): <private>: Successfully set up CloudKit integration for store (<private>): <private> CoreData+CloudKit: -[NSCloudKitMirroringDelegate _enqueueRequest:]_block_invoke(1035): Failed to enqueue request: <private> Error Domain=NSCocoaErrorDomain Code=134417 UserInfo={NSLocalizedFailureReason=<private>}

Hi, I'm having trouble implementing iCloud Drive in my app. I've already taken the obvious steps, including enabling iCloud Documents in Xcode and selecting a container. This container is correctly specified in my code, and in theory, everything should work. The data generated by my app should be saved to iCloud Drive in addition to local storage. The data does get stored in the Files app, but the automatic syncing to iCloud Drive doesn’t work as expected. I’ve also considered updating my .entitlements file. Since I’m at a loss, I’m reaching out for help maybe I’ve overlooked something important that's causing it not to work. If anyone has an idea, please let me know. Thanks in advance!

Hello, I'm planning to had an onboarding to one of my apps. I am thinking about a way for a user to not see the onboarding again if he installs the app on another device. So for example, the user completes the onboarding on its iPhone, then downloads the app on its iPad and launch it, he doesn't see the onboarding a second time. I thought about using iCloud NSUbiquitousKeyValueStored to store the onboarding completion state. But I'm not sure when the data is synced to the other device logged into the same Apple account: Immediately even if the app is not installed on the other device (independent from the app, only iCloud thing)? At the same time as the app install on the other device? After the app is first launched on the other device? Of course synchronisation will depend on the Internet connection, speed, etc. so the app should handle the case where the data is not here but what would be the best case scenario? Thank you, Axel

I have an app that I signed and distribute between some internal testflight users. Potentially I want to invite some 'Public' beta testers which don't need to validate (_World have read rights in the public database) Question: Do I need to have a working public CloudKit , when users are invited through TestFlight, or are they going to test on the development container? I understand that when I invite beta-tester without authorization (external testers) they cannot access the developer container, so therefore I need to have the production CloudKit container up and running. I have tried to populate the public production container, but for whatever reason my upload app still goes to the development container. I have archived the app, and tried, but no luck. I let xcode manage my certificates/profiles. but what do I need to change to be able to use my upload file to upload the production container, instead of the development. I tried: init() { container = CKContainer(identifier: "iCloud.com.xxxx.xxxx") publicDB = container.publicCloudDatabase I got no error in the console, but data is always populated to the development database, instead the production. I tried to create a provisioning profile, but for some reason Xcode doesn't like it. Tried to create one a different provisioning profile manual through the developer portal, for the app. but xcode doesn't want to use that, and mentions that the requirement are already in place. What can I check/do to solve this.

Hi, would it be possible that instead of crashing when calling fetchHistory that function simply throws an error instead? fetchHistory seems to crash when it cannot understand the models if they are not compatible etc… which is understandable, but it makes it really difficult to handle and debug, there's not a lot of details, and honestly I would just rather that it throws an error and let me ignore a history entry that might be useless rather than crashing the entire app. Thank you!

I have started from here: Apple's guide on the sharing core data objects between iCloud users and I have created a sample project that has Collections and Items. Everything works great while I stay on Swift 5, like with the initial project. I would like to migrate to Swift 6 (Default Actor Isolaton @MainActor, Approachable Concurrency: Yes) on the project and I am stuck at extension CDCollection: Transferable { ... }. When compiling with Swift 5, there is a warning: Conformance of 'NSManagedObject' to 'Sendable' is unavailable in iOS; this is an error in the Swift 6 language mode. After resolving almost all compile-time warnings I'm left with: Conformance of 'CDCollection' to protocol 'Transferable' crosses into main actor-isolated code and can cause data races. Which I don't think will work, because of the warning shown above. It can be worked around like: nonisolated extension CDCollection: Transferable, @unchecked Sendable Then there are errors: let persistentContainer = PersistenceController.shared.persistentContainer Main actor-isolated static property 'shared' can not be referenced from a nonisolated context. I've created the following class to have a Sendable object: struct CDCollectionTransferable: Transferable { var objectID: NSManagedObjectID var persistentContainer: NSPersistentCloudKitContainer public static var transferRepresentation: some TransferRepresentation { CKShareTransferRepresentation { collectionToExport in let persistentContainer = collectionToExport.persistentContainer let ckContainer = CloudKitProvider.container var collectionShare: CKShare? if let shareSet = try? persistentContainer.fetchShares( matching: [collectionToExport.objectID]), let (_, share) = shareSet.first { collectionShare = share } /** Return the existing share if the collection already has a share. */ if let share = collectionShare { return .existing(share, container: ckContainer) } /** Otherwise, create a new share for the collection and return it. Use uriRepresentation of the object in the Sendable closure. */ let collectionURI = collectionToExport.objectID .uriRepresentation() return .prepareShare(container: ckContainer) { let collection = await persistentContainer.viewContext .perform { let coordinator = persistentContainer.viewContext .persistentStoreCoordinator guard let objectID = coordinator?.managedObjectID( forURIRepresentation: collectionURI ) else { fatalError( "Failed to return the managed objectID for: \(collectionURI)." ) } return persistentContainer.viewContext.object( with: objectID ) } let (_, share, _) = try await persistentContainer.share( [collection], to: nil ) return share } } } } And I'm able to compile and run the app with this change: let transferable = CDCollectionTransferable( objectID: collection.objectID, persistentContainer: PersistenceController.shared .persistentContainer ) ToolbarItem { ShareLink( item: transferable, preview: SharePreview("Share \(collection.name)!") ) { MenuButtonLabel( title: "New Share", systemImage: "square.and.arrow.up" ) } } The app crashes when launched with libdispatch.dylib`_dispatch_assert_queue_fail: 0x1052c6ea4 <+0>: sub sp, sp, #0x50 0x1052c6ea8 <+4>: stp x20, x19, [sp, #0x30] 0x1052c6eac <+8>: stp x29, x30, [sp, #0x40] 0x1052c6eb0 <+12>: add x29, sp, #0x40 0x1052c6eb4 <+16>: adrp x8, 63 0x1052c6eb8 <+20>: add x8, x8, #0xa0c ; "not " 0x1052c6ebc <+24>: adrp x9, 62 0x1052c6ec0 <+28>: add x9, x9, #0x1e5 ; "" 0x1052c6ec4 <+32>: stur xzr, [x29, #-0x18] 0x1052c6ec8 <+36>: cmp w1, #0x0 0x1052c6ecc <+40>: csel x8, x9, x8, ne 0x1052c6ed0 <+44>: ldr x10, [x0, #0x48] 0x1052c6ed4 <+48>: cmp x10, #0x0 0x1052c6ed8 <+52>: csel x9, x9, x10, eq 0x1052c6edc <+56>: stp x9, x0, [sp, #0x10] 0x1052c6ee0 <+60>: adrp x9, 63 0x1052c6ee4 <+64>: add x9, x9, #0x9db ; "BUG IN CLIENT OF LIBDISPATCH: Assertion failed: " 0x1052c6ee8 <+68>: stp x9, x8, [sp] 0x1052c6eec <+72>: adrp x1, 63 0x1052c6ef0 <+76>: add x1, x1, #0x9a6 ; "%sBlock was %sexpected to execute on queue [%s (%p)]" 0x1052c6ef4 <+80>: sub x0, x29, #0x18 0x1052c6ef8 <+84>: bl 0x105301b18 ; symbol stub for: asprintf 0x1052c6efc <+88>: ldur x19, [x29, #-0x18] 0x1052c6f00 <+92>: str x19, [sp] 0x1052c6f04 <+96>: adrp x0, 63 0x1052c6f08 <+100>: add x0, x0, #0xa11 ; "%s" 0x1052c6f0c <+104>: bl 0x1052f9ef8 ; _dispatch_log 0x1052c6f10 <+108>: adrp x8, 95 0x1052c6f14 <+112>: str x19, [x8, #0x1f0] -> 0x1052c6f18 <+116>: brk #0x1 The app still crashes when I comment this code, and all Core Data related warnings. I'm quite stuck now as I want to use Swift 6. Has anyone figured CloudKit, CoreData and Swift 6 for sharing between users?