Hi everyone, Have anybody faced with Core Data issues, trying to migrate the project to Xcode16 beta 4? We are using transformableAttributeType in some entities, with attributeValueClassName = "[String]" and valueTransformerName = "NSSecureUnarchiveFromData". It is working just fine for years, but now I am trying to run the project from Xcode16 and have 2 issues: in Xcode logs I see warning and error: CoreData: fault: Declared Objective-C type "[String]" for attribute named alertBarChannels is not valid CoreData: Declared Objective-C type "[String]" for attribute named alertBarChannels is not valid periodically the app crashes when we are assigning value to this attribute, with error: Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFConstantString characterAtIndex:]: Range or index out of bounds' Once again, in Xcode 15 it works fine, and it was working for years. Cannot find any information about what was changed in the framework... Thank you in advance for any information, which could clarify what is going on.

The NSPersistentCloudKitContainer synchronization between core data and iCloud was working fine with phone 15.1. Connected a new iPhone iOS 15.5, it gives error: CoreData: debug: CoreData+CloudKit: -[NSCloudKitMirroringDelegate managedObjectContextSaved:](2504): <NSCloudKitMirroringDelegate: 0x28198c000>: Observed context save: <NSPersistentStoreCoordinator: 0x2809c9420> - <NSManagedObjectContext: 0x2819ad520> 2022-12-05 13:32:28.377000-0600 r2nr[340:6373] [error] error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _importFinishedWithResult:importer:](1245): <PFCloudKitImporter: 0x2837dd740>: Import failed with error: Error Domain=NSCocoaErrorDomain Code=4864 "*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)" UserInfo={NSDebugDescription=*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)} CoreData: error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _importFinishedWithResult:importer:](1245): <PFCloudKitImporter: 0x2837dd740>: Import failed with error: Error Domain=NSCocoaErrorDomain Code=4864 "*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)" UserInfo={NSDebugDescription=*** -[NSKeyedUnarchiver _initForReadingFromData:error:throwLegacyExceptions:]: incomprehensible archive (0x53, 0x6f, 0x6d, 0x65, 0x20, 0x65, 0x78, 0x61)} I go back and try with my old iPhone iOS 15.1, gives same error.

I'm using NSPersistentCloudKitContainer with Core Data and I receive errors because my iCloud space is full. The errors printed are the following: <CKError 0x280df8e40: "Quota Exceeded" (25/2035); server message = "Quota exceeded"; op = 61846C533467A5DF; uuid = 6A144513-033F-42C2-9E27-693548EF2150; Retry after 342.0 seconds>. I want to inform the user about this issue, but I can't find a way to access the details of the error. I'm listening to NSPersistentCloudKitContainer.eventChangedNotification, I receive a error of type .partialFailure. But when I want to access the underlying errors, the partialErrorsByItemID property on the error is nil. How can I access this Quota Exceeded error? import Foundation import CloudKit import Combine import CoreData class SyncMonitor { fileprivate var subscriptions = Set<AnyCancellable>() init() { NotificationCenter.default.publisher(for: NSPersistentCloudKitContainer.eventChangedNotification) .sink { notification in if let cloudEvent = notification.userInfo?[NSPersistentCloudKitContainer.eventNotificationUserInfoKey] as? NSPersistentCloudKitContainer.Event { guard let ckerror = cloudEvent.error as? CKError else { return } print("Error: \(ckerror.localizedDescription)") if ckerror.code == .partialFailure { guard let errors = ckerror.partialErrorsByItemID else { return } for (_, error) in errors { if let currentError = error as? CKError { print(currentError.localizedDescription) } } } } } // end of sink .store(in: &subscriptions) } }

I am using SwiftData for my model. Until Xcode 15 beta 4 I did not have issues. Since beta 5 I am receiving the following red warning multiple times: 'NSKeyedUnarchiveFromData' should not be used to for un-archiving and will be removed in a future release This seems to be a CoreData warning. However, I am not using CoreData directly. I have no way to change the config of CoreData as used by SwiftData. My model just uses UUID, Int, String, Double, some of them as optionals or Arrays. I only use one attribute (.unique).

I have an image field on a Core Data entity with "Allows External Storage" enabled. When I delete a record, the external binary data file remains on disk. How can I ensure that all externally stored data is deleted along with the record?

Hi everyone! I have an app on the App Store that uses Core Data as its data store. (It's called Count on Me: Tally Counter. Feel free to check it out.) One of the app's core feature is an interactive widget with a simple button. When the button is tapped, it's supposed to update the entity in the store. My requirement is that the changes are then reflected with minimal latency in the main app and – ideally – also on other devices of the same iCloud user. And vice-versa: When an entity is updated in the app (or on another device where the same iCloud user is logged in), the widget that shows this entity should also refresh to reflect the changes. I have read multiple articles, downloaded sample projects, searched Stackoverflow and the Apple developer forums, and tried to squeeze a solution out of AI, but couldn't figure out how to make this work reliably. So I tried to reduce the core problem to a minimal example project. It has two issues that I cannot resolve: When I update an entity in the app, the widget is immediately updated as intended (due to a call to WidgetCenter's reloadAllTimelines method). However, when I update the same entity from the interactive widget using the same app intent, the changes are not reflected in the main app. For the widget and the app to use the same local data store, I need to enable App Groups in both targets and set a custom location for the store within the shared app group. So I specify a custom URL for the NSPersistentStoreDescription when setting up the Core Data stack. The moment I do this, iCloud sync breaks. Issue no. 1 is far more important to me as I haven't officially enabled iCloud sync yet in my real app that's already on the App Store. But it would be wonderful to resolve issue no. 2 as well. Surely, there must be a way to synchronize changes to the source of truth triggered by interactive widget with other devices of the same iCloud user. Otherwise, the feature to talk to the main app and the feature to synchronize with iCloud would be mutually exclusive. Some other developers I talked to have suggested that the widget should only communicate proposed changes to the main app and once the main app is opened, it processes these changes and writes them to the NSPersistentCloudKitContainer which then synchronizes across devices. This is not an option for me as it would result in a stale state and potential data conflicts with different devices. For example, when a user has the same widget on their iPhone and their iPad, taps a button on the iPhone widget, that change would not be reflected on the iPad widget until the user decides to open the app on the iPhone. At the same time, the user could tap the button multiple times on their iPad widget, resulting in a conflicting state on both devices. Thus, this approach is not a viable solution. An answer to this question will be greatly appreciated. The whole code including the setup of the Core Data stack is included in the repository reference above. Thank you!

I am experiencing an issue where XCode reverts .xccurrentversion file in my iOS app to the first version whenever xcodebuild is run or whenever XCode is started. This means I can build the app and run tests in XCode if I discard the reversion .xccurrentversion on XCode start. However, testing on CI is impossible because the version the tests rely on are reverted whenever xcodebuild is run. The commands I run to reproduce the issue ❯ git status Changes not staged for commit: (use "git add <file>..." to update what will be committed) (use "git restore <file>..." to discard changes in working directory) modified: Path/.xccurrentversion no changes added to commit (use "git add" and/or "git commit -a") ❯ git checkout "Path/.xccurrentversion" Updated 1 path from the index ❯ git status nothing to commit, working tree clean ❯ xcodebuild \ -scheme Scheme \ -configuration Configuration \ -sdk iphonesimulator \ -destination 'platform=iOS Simulator,name=iPhone 16 Pro,OS=latest' \ -skipPackagePluginValidation \ -skipMacroValidation \ test > /dev/null # test fails because model version is reverted ❯ git status HEAD detached at pull/249/merge Changes not staged for commit: (use "git add <file>..." to update what will be committed) (use "git restore <file>..." to discard changes in working directory) modified: Path/.xccurrentversion no changes added to commit (use "git add" and/or "git commit -a") I have experienced such issue in 16.3 (16E140) and 16.2 (16C5032a). Similar issues/solutions I have found online are the following. But they are either not relevant or do not work in my case. https://stackoverflow.com/questions/17631587/xcode-modifies-current-coredata-model-version-at-every-launch https://github.com/CocoaPods/Xcodeproj/issues/81 Is anyone aware of any solution? Is there a recommended way I can run diagnostics on XCode and file a feedback?

Hi, I work on a financial app in Brazil and since Beta 1 we're getting several crashes. We already opened a code level support and a few feedback issues, but haven't got any updates on that yet. We were able to resolve some crashes changing some of our implementation but we aren't able to understand what might be happening with this last one. This is the log we got on console: erro 11:55:41.805875-0300 MyApp CoreData: error: Failed to load NSManagedObjectModel with URL 'file:///private/var/containers/Bundle/Application/0B9F47D9-9B83-4CFF-8202-3718097C92AE/MyApp.app/ServerDrivenModel.momd/' We double checked and the momd is inside the bundle. The same app works on any other iOS version and if we build using Xcode directly (without archiving and installing on an iOS26 device) it works as expected. Have anyone else faced a similar error? Any tips or advice on how we can try to solve that?

I am planning a Core Data migration for a macOS app targeting macOS 12 and later and I would appreciate guidance on structuring the rollout to minimise risk. Context The app currently uses a SQLite store located at: ~/Library/Containers/com.company.AppName/Data/Library/Application Support/AppName I want to: Relocate the persistent store to an app group container: ~/Library/Group Containers/group.com.company.AppName Perform schema migration, including: Renaming attributes Deleting attributes Using a custom NSEntityMigrationPolicy subclass Adopt iCloud sync using NSPersistentCloudKitContainer Potentially leverage staged migration (macOS 14+) Additionally, I intend to port the app to iOS, so the end state needs to support an app group container and CloudKit with the latest schema from the outset. Questions Store relocation vs schema migration Is it advisable to perform store relocation and schema migration in a single step, or should these be separate releases? If combined, are there pitfalls when moving the SQLite file and running a migration in the same launch cycle? Custom migration policy Any best practices for structuring NSEntityMigrationPolicy when also relocating the store? Should migration policies assume the store has already been moved, or handle both concerns? Staged migration (macOS 14+) Is staged migration worth adopting when still supporting macOS 12–13? Would you gate it conditionally, or avoid it entirely for consistency? CloudKit adoption Is introducing NSPersistentCloudKitContainer in the same release as the above migrations too risky? Are there known issues when enabling CloudKit immediately after a migration? Release strategy Would you recommend: A single release handling everything Two phases: (1) store & schema migration, (2) CloudKit Or three phases: store relocation → schema migration → CloudKit Goal I want a smooth, reliable transition without data loss or duplication, particularly for existing users with non-trivial datasets. Any insights, practical experience, or recommended sequencing strategies would be very helpful.

Hello guys, this is my first post to this forum and really hope that somebody can help me here. I would highly appreciate every help! I am writing my first app with Swift UI (never used UIKit before) which I want to publish later on. This is also my first app which has CoreData implemented. For example I use the following entities: Family, Person 1 Persons can have 1 Family 1 Family can have many Persons My App is structured as the following: ContentView: Contains a TabView with 2 other views in it. A Settings View and a View with a LazyVGrid. LazyVGrid View: This View shows a GridItem for every Family. I get the Families with the following Fetchrequest: @Environment(\.managedObjectContext) private var viewContext // These are the Families from the FetchRequest @FetchRequest(entity: Family.entity(), sortDescriptors: [NSSortDescriptor(keyPath: \Family.created, ascending: false)] ) var families: FetchedResults<Family> Every GridItem is linking to a "FamilyDetailView" via NavigationLink. So i pass the family as the following: NavigationLink(destination: FamilyDetailView(family: family).environment(\.managedObjectContext, self.viewContext), label: {Text("Family Name") In the FamilyDetailView i get the Family with a property wrapper: @State var family : Family In this FamilyDetailView is the problem i have. Here I also have a LazyVGrid, which shows 1 NavigationLink for every Person in the Family in a GridItem . In this GridItem I also show for example the "name" of the Person. When tapping the NavigationLink i get to the last View, the PersonDetailView. This View gets the Person which is also an entity which has a relationship to the Family Entity. I pass it as the follow: NavigationLink( destination: PersonDetailView(person: person), label: {Text("Person")}) In the PersonDetailView I now change the name of the person and save the changed to CoreData. The change is saved without a problem, the problem is that when I go back, using the topleading back button from the NavigationView, the Views are not updated. I have to restart the App to see the changes.. I know that the Problem has to be with passing the Data, but I cant figuring out what I did wrong. I really appreciate everyone trying to help me! Thank you very very much!!

Background I have an established app in the App Store which has been using NSPersistentCloudkitContainer since iOS 13 without any issues. I've been running my app normally on an iOS device running the iOS 15 betas, mainly to see problems arise before my users see them. Ever since iOS 15 (beta 4) my app has failed to sync changes - no matter how small the change. An upload 'starts' but never completes. After a minute or so the app quits to the Home Screen and no useful information can be gleaned from crash reports. Until now I've had no idea what's going on. Possible Bug in the API? I've managed to replicate this behaviour on the simulator and on another device when building my app with Xcode 13 (beta 5) on iOS 15 (beta 5). It appears that NSPersistentCloudkitContainer has a memory leak and keeps ramping up the RAM consumption (and CPU at 100%) until the operating system kills the app. No code of mine is running. I'm not really an expert on these things and I tried to use Instruments to see if that would show me anything. It appears to be related to NSCloudkitMirroringDelegate getting 'stuck' somehow but I have no idea what to do with this information. My Core Data database is not tiny, but not massive by any means and NSPersistentCloudkitContainer has had no problems syncing to iCloud prior to iOS 15 (beta 4). If I restore my App Data (from an external backup file - 700MB with lots of many-many, many-one relationships, ckAssets, etc.) the data all gets added to Core Data without an issue at all. The console log (see below) then shows that a sync is created, scheduled & then started... but no data is uploaded. At this point the memory consumption starts and all I see is 'backgroundTask' warnings appear (only related to CloudKit) with no code of mine running. CoreData: CloudKit: CoreData+CloudKit: -[PFCloudKitExporter analyzeHistoryInStore:withManagedObjectContext:error:](501): <PFCloudKitExporter: 0x600000301450>: Exporting changes since (0): <NSPersistentHistoryToken - { "4B90A437-3D96-4AC9-A27A-E0F633CE5D9D" = 906; }> CoreData: CloudKit: CoreData+CloudKit: -[PFCloudKitExportContext processAnalyzedHistoryInStore:inManagedObjectContext:error:]_block_invoke_3(251): Finished processing analyzed history with 29501 metadata objects to create, 0 deleted rows without metadata. CoreData: CloudKit: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _scheduleAutomatedExportWithLabel:activity:completionHandler:](2800): <NSCloudKitMirroringDelegate: 0x6000015515c0> - Beginning automated export - ExportActivity: <CKSchedulerActivity: 0x60000032c500; containerID=<CKContainerID: 0x600002ed3240; containerIdentifier=iCloud.com.nitramluap.Somnus, containerEnvironment="Sandbox">, identifier=com.apple.coredata.cloudkit.activity.export.4B90A437-3D96-4AC9-A27A-E0F633CE5D9D, priority=2, xpcActivityCriteriaOverrides={ Priority=Utility }> CoreData: CloudKit: CoreData+CloudKit: -[NSCloudKitMirroringDelegate executeMirroringRequest:error:](765): <NSCloudKitMirroringDelegate: 0x6000015515c0>: Asked to execute request: <NSCloudKitMirroringExportRequest: 0x600002ed2a30> CBE1852D-7793-46B6-8314-A681D2038B38 2021-08-13 08:41:01.518422+1000 Somnus[11058:671570] [BackgroundTask] Background Task 68 ("CoreData: CloudKit Export"), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination. Remember to call UIApplication.endBackgroundTask(_:) for your task in a timely manner to avoid this. 2021-08-13 08:41:03.519455+1000 Somnus[11058:671570] [BackgroundTask] Background Task 154 ("CoreData: CloudKit Scheduling"), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination. Remember to call UIApplication.endBackgroundTask(_:) for your task in a timely manner to avoid this. Just wondering if anyone else is having a similar issue? It never had a problem syncing an initial database restore prior to iOS 15 (beta 4) and the problems started right after installing iOS 15 (beta 4). I've submitted this to Apple Feedback and am awaiting a response (FB9412346). If this is unfixable I'm in real trouble (and my users are going to be livid). Thanks in advance!

When my app starts it loads data (of vehicle models, manufacturers, ...) from JSON files into CoreData.  This content is static. Some CoreData entities have fields that can be set by the user, for example an isFavorite boolean field. How do I tell CloudKit that my CoreData objects are 'static' and must not be duplicated on other devices (that will also load it from JSON files). In other words, how can I make sure that the CloudKit knows that the record created from JSON for vehicle model XYZ on one device is the same record that was created from JSON on any other device? I'm using NSPersistentCloudKitContainer.

I'm building a macOS + iOS SwiftUI app using Xcode 14.1b3 on a Mac running macOS 13.b11. The app uses Core Data + CloudKit. With development builds, CloudKit integration works on the Mac app and the iOS app. Existing records are fetched from iCloud, and new records are uploaded to iCloud. Everybody's happy. With TestFlight builds, the iOS app has no problems. But CloudKit integration isn't working in the Mac app at all. No existing records are fetched, no new records are uploaded. In the Console, I see this message: error: CoreData+CloudKit: Failed to set up CloudKit integration for store: <NSSQLCore: 0x1324079e0> (URL: <local file url>) Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.cloudd was invalidated: failed at lookup with error 159 - Sandbox restriction." UserInfo={NSDebugDescription=The connection to service named com.apple.cloudd was invalidated: failed at lookup with error 159 - Sandbox restriction.} I thought it might be that I was missing the com.apple.security.network.client entitlement, but adding that didn't help. Any suggestions what I might be missing? (It's my first sandboxed Mac app, so it might be really obvious to anyone but me.)

I have been using the basic NSPersistentContainer with 100k+ records for a while now with no issues. The database size can fluctuate a bit but on average it takes up about 22mb on device. When I switch the container to NSPersistentCloudKitContainer, I see a massive increase in size to ~150mb initially. As the sync engine uploads records to iCloud it has ballooned to over 600mb on device. On top of that, the user's iCloud usage in settings reports that it takes up 1.7gb in the cloud. I understand new tables are added and history tracking is enabled but the size increase seems a bit drastic. I'm not sure how we got from 22mb to 1.7gb with the exact same data. A few other things that are important to note: I import all the 100k+ records at once when testing the different containers. At the time of the initial import there is only 1 relation (an import group record) that all the records are attached to. I save the background context only once after all the records and the import group have been made and added to the context. After the initial import, some of these records may have a few new relations added to them over time. I suppose this could be causing some of the size increase, but its only about 20,000 records that are updated. None of the records include files/ large binary data. Most of the attributes are encrypted. I'm syncing to the dev iCloud environment. When I do make a change to a single attribute in a record, CloudKit reports that every attribute has been modified (not sure if this is normal or not ) Also, When syncing to a new device, the sync can take hours - days. I'm guessing it's having to sync both the new records and the changes, but it exponentially gets slower as more records are downloaded. The console will show syncing activity, but new records are being added at a slower rate as more records are added. After about 50k records, it grinds to a halt and while the console still shows sync activity, only about 100 records are added every hour. All this to say i'm very confused where these issues are coming from. I'm sure its a combination of how i've setup my code and the vast record count, record history, etc. If anyone has any ideas it would be much appreciated.

I have this very simple PersistenceController setup. It's used in both the main app and widget target. struct PersistenceController { static let shared = PersistenceController() @MainActor static let preview: PersistenceController = { let result = PersistenceController(inMemory: true) let viewContext = result.container.viewContext return result }() let container: NSPersistentContainer /// The main context. var context: NSManagedObjectContext { return container.viewContext } init(inMemory: Bool = false) { container = NSPersistentContainer(name: "Gamery") if inMemory { container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null") } else { do { let storeURL = try URL.storeURL(forAppGroup: "XXXXXXXXXX", databaseName: "Gamery") let storeDescription = NSPersistentStoreDescription(url: storeURL) /// Enable history tracking for cloud syncing purposes. storeDescription.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey) print("### Persistent container location: \(storeURL)") container.persistentStoreDescriptions = [storeDescription] } catch { print("Failed to retrieve store URL for app group: \(error)") } } container.loadPersistentStores(completionHandler: { (storeDescription, error) in if let error = error as NSError? { Crashlytics.crashlytics().record(error: error) fatalError("Unresolved error \(error), \(error.userInfo)") } }) container.viewContext.automaticallyMergesChangesFromParent = true container.viewContext.mergePolicy = NSMergePolicy.mergeByPropertyObjectTrump #if !WIDGET if !inMemory { do { try container.viewContext.setQueryGenerationFrom(.current) } catch { fatalError("###\(#function): Failed to pin viewContext to the current generation: \(error)") } } PersistentHistoryToken.loadToken() #endif } } I regularly receive crash logs from the widget. I never experienced crashes myself and the widgets work fine. GameryWidgetExtension/PersistenceController.swift:35: Fatal error: Unresolved error Error Domain=NSCocoaErrorDomain Code=256 "The file “Gamery.sqlite” couldn’t be opened." UserInfo={NSFilePath=/private/var/mobile/Containers/Shared/AppGroup/B6A63FE1-ADDC-4A4C-A065-163507E991C6/Gamery.sqlite, NSSQLiteErrorDomain=23}, ["NSSQLiteErrorDomain": 23, "NSFilePath": /private/var/mobile/Containers/Shared/AppGroup/B6A63FE1-ADDC-4A4C-A065-163507E991C6/Gamery.sqlite] I have absolutely no idea what's going on here. Anyone who can help with this?

Hey there! I've been tracking a really weird behavior with a List backed by @FetchRequest from CoreData. When I toggle a bool on the CoreData model, the first time it updates correctly, but if I do it a second time, the UI doesn't re-render as expected. This does not happen if I compile the app using Xcode 16 (targeting both iOS 18 and iOS 26), nor it happens when using Xcode 26 and targeting iOS 18. It only happens when building the app using Xcode 26 and running it on iOS 26. Here are two demos: the first one works as expected, when I toggle the state twice, both times updates. The second one, only on iOS 26, the second toggle fails to re-render. Demo (running from Xcode 16): Demo (running from Xcode 26): The code: import SwiftUI import CoreData @main struct CoreDataTestApp: App { let persistenceController = PersistenceController.shared var body: some Scene { WindowGroup { ContentView() .environment(\.managedObjectContext, persistenceController.container.viewContext) } } } struct ContentView: View { @Environment(\.managedObjectContext) private var viewContext @FetchRequest(sortDescriptors: [NSSortDescriptor(keyPath: \Item.timestamp, ascending: true)]) private var items: FetchedResults<Item> var body: some View { NavigationView { List { ForEach(items) { item in HStack { Text(item.timestamp!.formatted()) Image(systemName: item.isFavorite ? "heart.fill" : "heart").foregroundStyle(.red) }.swipeActions(edge: .leading, allowsFullSwipe: true) { Button(item.isFavorite ? "Unfavorite" : "Favorite", systemImage: item.isFavorite ? "heart" : "heart.fill") { toggleFavoriteStatus(item: item) } } } } .toolbar { ToolbarItem { Button(action: addItem) { Label("Add Item", systemImage: "plus") } } } } } private func addItem() { withAnimation { let newItem = Item(context: viewContext) newItem.timestamp = Date() newItem.isFavorite = Bool.random() try! viewContext.save() } } private func toggleFavoriteStatus(item: Item) { withAnimation { item.isFavorite.toggle() try! viewContext.save() } } } struct PersistenceController { static let shared = PersistenceController() let container: NSPersistentContainer init() { container = NSPersistentContainer(name: "CoreDataTest") container.loadPersistentStores(completionHandler: { _, _ in }) container.viewContext.automaticallyMergesChangesFromParent = true } }

I have some code which handles doing some computation on a background thread before updating Core Data NSManagedObjects by using the NSManagedObjectContext.perform functions. This code is covered in Sendable warnings in Xcode 26 (beta 6) because my NSManagedObject subclasses (autogenerated) are non-Sendable and NSManagedObjectContext.perform function takes a Sendable closure. But I can't really figure out what I should be doing. I realize this pattern is non-ideal for Swift concurrency, but it's what Core Data demands AFAIK. How do I deal with this? let moc = object.managedObjectContext! try await moc.perform { object.completed = true // Capture of 'object' with non-Sendable type 'MySpecialObject' in a '@Sendable' closure try moc.save() } Thanks in advance for your help!

I am working on a SwiftUI project using Core Data. I have an entity called AppleUser in my data model, with the following attributes: id (UUID), name (String), email (String), password (String), and createdAt (Date). All attributes are non-optional. I created the corresponding Core Data class files (AppleUser+CoreDataClass.swift and AppleUser+CoreDataProperties.swift) using Xcode’s automatic generation. I also have a PersistenceController that initializes the NSPersistentContainer with the model name JobLinkModel. When I try to save a new AppleUser object using: let user = AppleUser(context: viewContext) user.id = UUID() user.name = "User1" user.email = "..." user.password = "password1" user.createdAt = Date()【The email is correctly formatted, but it has been replaced with “…” for privacy reasons】 try? viewContext.save() I get the following error in the console:Core Data save failed: Foundation._GenericObjCError.nilError, [:] User snapshot: ["id": ..., "name": "User1", "email": "...", "password": "...", "createdAt": ...] All fields have valid values, and the Core Data model seems correct. I have also tried: • Checking that the model name in NSPersistentContainer(name:) matches the .xcdatamodeld file (JobLinkModel) • Ensuring the AppleUser entity Class, Module, and Codegen are correctly set (Class Definition, Current Product Module) • Deleting duplicate or old AppleUser class files • Cleaning Xcode build folder and deleting the app from the simulator • Using @Environment(.managedObjectContext) for the context Despite all this, I still get _GenericObjCError.nilError when saving a new AppleUser object. I want to understand: 1. Why is Core Data failing to save even though all fields are non-nil and correctly assigned? 2. Could this be caused by some residual old class files, or is there something else in the setup that I am missing? 3. What steps should I take to ensure that Core Data properly recognizes the AppleUser entity and allows saving? Any help or guidance would be greatly appreciated.

I'm having an issue where FetchRequest does not consistently reflect changes that are made in the CoreData model. Things seem to work fine if you create or delete any object before editing, but if you only edit an object, the changes will not be shown. Here is a minimal repro: https://github.com/literalpie/fetchrequest-bug/tree/main I have a workaround that involved adding a "noop" predicate that gets toggled whenever objectWillChange is emitted. This seems to force the FetchRequest to re-look at things. .onReceive(items.publisher.flatMap(\.objectWillChange), perform: { _ in items.nsPredicate = update ? NSPredicate(value: true) : NSPredicate(format: "1 == 1") update.toggle() })

Hello Apple Team, We’re building a CloudKit-enabled Core Data app and would like clarification on the behavior and performance characteristics of Binary Data attributes with “Allows External Storage” enabled when used with NSPersistentCloudKitContainer. Initially, we tried storing image files manually on disk and only saving the metadata (file URLs, dimensions, etc.) in Core Data. While this approach reduced the size of the Core Data store, it introduced instability after app updates and broke sync between devices. We would prefer to use the official Apple-recommended method and have Core Data manage image storage and CloudKit syncing natively. Specifically, we’d appreciate guidance on the following: When a Binary Data attribute is marked as “Allows External Storage”, large image files are stored as separate files on device rather than inline in the SQLite store. How effective is this mechanism in keeping the Core Data store size small on device? Are there any recommended size thresholds or known limits for how many externally stored blobs can safely be managed this way? How are these externally stored files handled during CloudKit sync? Does each externally stored Binary Data attribute get mirrored to CloudKit as a CKAsset? Does external storage reduce the sync payload size or network usage, or is the full binary data still uploaded/downloaded as part of the CKAsset? Are there any bandwidth implications for users syncing via their private CloudKit database, versus developer costs in the public CloudKit database? Is there any difference in CloudKit or Core Data behavior when a Binary Data attribute is managed this way versus manually storing image URLs and handling the file separately on disk? Our goal is to store user-generated images efficiently and safely sync them via CloudKit, without incurring excessive local database bloat or CloudKit network overhead. Any detailed guidance or internal performance considerations would be greatly appreciated. Thank you, Paul Barry Founder & Lead Developer — Boat Buddy / Vessel Buddy iOS App Archipelago Environmental Solutions Inc.