I'm experiencing the following error with my SwiftData container when running a build:
Code=134504 "Cannot use staged migration with an unknown model version."
Code Structure - Summary
I am using a versionedSchema to store multiple models in SwiftData. I started experiencing this issue when adding two new models in the newest Schema version. Starting from the current public version, V4.4.6, there are two migrations.
Migration Summary
The first migration is to V4.4.7. This is a lightweight migration removing one attribute from one of the models. This was tested and worked successfully.
The second migration is to V5.0.0. This is a custom migration adding two new models, and instantiating instances of the two new models based on data from instances of the existing models. In the initial testing of this version, no issues were observed.
Issue and Steps to Reproduce
Reproduction of issue: Starting from a fresh build of the publicly released V4.4.6, I run a new build that contains both Schema Versions (V4.4.7 and V5.0.0), and their associated migration stages. This builds successfully, and the container successfully migrates to V5.0.0. Checking the default.store file, all values appear to migrate and instantiate correctly.
The second step in reproduction of the issue is to simply stop running the build, and then rebuild, without any code changes. This fails to initialize the model container every time afterwards. Going back to the simulator after successive builds are stopped in Xcode, the app launches and accesses/modifies the model container as normal.
Supplementary Issue: I have been putting up with the same, persistent issue in the Xcode Preview Canvas of "Failed to Initialize Model Container" This is a 5 in 6 build issue, where builds will work at random. In the case of previews, I have cleared all data associated with all previews multiple times. The only difference being that the simulator is a 100% failure rate after the initial, successful initialization. I assume this is due to the different build structure of previews. Lastly, of note, the Xcode previews fail at the same line in instantiating the model container as the simulator does. From my research into this issue, people say that the Xcode preview is instantiating from elsewhere. I do have a separate model container set up specifically for canvas previews, but the error does not occur in that container, but rather the app's main container.
Possible Contributing Factors & Tested Facts
iOS: While I have experienced issues with SwiftData and the complier in iOS 26, I can rule that out as the issue here. This has been tested on simulators running iOS 18.6, 26.0.1, and 26.1, all encountering failures to initialize model container. While in iOS 18, subsequent builds after the successful migration did work, I did eventually encounter the same error and crash. In iOS 26.0.1 and 26.1, these errors come immediately on the second build.
Container Initialization for V4.4.6
do {
container = try ModelContainer(
for:
Job.self,
JobTask.self,
Day.self,
Charge.self,
Material.self,
Person.self,
TaskCategory.self,
Service.self,
migrationPlan: JobifyMigrationPlan.self
)
} catch {
fatalError("Failed to Initialize Model Container")
}
Versioned Schema Instance for V4.4.6 (V4.4.7 differs only by versionIdentifier)
static var versionIdentifier = Schema.Version(4, 4, 6)
static var models: [any PersistentModel.Type] {
[Job.self, JobTask.self, Day.self, Charge.self, Material.self, Person.self, TaskCategory.self, Service.self]
}
Container Initialization for V5.0.0
do {
let schema = Schema([Jobify.self,
JobTask.self,
Day.self,
Charge.self,
MaterialItem.self,
Person.self,
TaskCategory.self,
Service.self,
ServiceJob.self,
RecurerRule.self])
container = try ModelContainer(
for: schema, migrationPlan: JobifyMigrationPlan.self
)
} catch {
fatalError("Failed to Initialize Model Container")
}
Versioned Schema Instance for V5.0.0
static var versionIdentifier = Schema.Version(5, 0, 0)
static var models: [any PersistentModel.Type] {
[
JobifySchemaV500.Job.self,
JobifySchemaV500.JobTask.self,
JobifySchemaV500.Day.self,
JobifySchemaV500.Charge.self,
JobifySchemaV500.Material.self,
JobifySchemaV500.Person.self,
JobifySchemaV500.TaskCategory.self,
JobifySchemaV500.Service.self,
JobifySchemaV500.ServiceJob.self,
JobifySchemaV500.RecurerRule.self
]
}
Addressing Differences in Object Names
Type-aliasing: All my model types are type-aliased for simplification in view components. All types are aliased as 'JobifySchemeV446.<#Name#>' in V.4.4.6, and 'JobifySchemaV500.<#Name#>' in V5.0.0
Issues with iOS 26: My type-aliases dating back to iOS 17 overlapped with lower level objects in Swift, including 'Job' and 'Material'. These started to be an issue with initializing the model container when running in iOS 26. The type aliases have been renamed since, however the V4.4.6 build with the old names runs and builds perfectly fine in iOS 26
If there is any other code that may be relevant in determining where this error is occurring, I would be happy to add it. My current best theory is simply that I have mistakenly omitted code relevant to the SwiftData Migration.
iCloud & Data
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My app uses iCloud to let users sync their files via their private iCloud Drive, which does not use CloudKit.
FileManager.default.url(forUbiquityContainerIdentifier: nil)?.appending(component: "Documents")
I plan to transfer my app to another developer account, but I'm afraid it will affect the access of the app to the existing files in that folder. Apple documentation doesn't mention this case.
Has anyone done this before and can confirm if the app will continue to work normally after transferring?
Thanks
In core-data I have a contact and location entity. I have one-to-many relationship from contact to locations and one-to-one from location to contact. I create contact in a seperate view and save it. Later I create a location, fetch the created contact, and save it while specifying the relationship between location and contact contact and test if it actually did it and it works.
viewContext.perform {
do {
// Set relationship using the generated accessor method
currentContact.addToLocations(location)
try viewContext.save()
print("Saved successfully. Locations count:", currentContact.locations?.count ?? 0)
if let locs = currentContact.locations {
print("📍 Contact has \(locs.count) locations.")
for loc in locs {
print("➡️ Location: \(String(describing: (loc as AnyObject).locationName ?? "Unnamed"))")
}
}
} catch {
print("Failed to save location: \(error.localizedDescription)")
}
}
In my NSManagedObject class properties I have this : for Contact:
@NSManaged public var locations: NSSet?
for Location:
@NSManaged public var contact: Contact?
in my persistenceController I have:
for desc in [publicStore, privateStore] {
desc.setOption(true as NSNumber, forKey:
NSPersistentStoreRemoteChangeNotificationPostOptionKey)
desc.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
desc.setOption(true as NSNumber, forKey: NSMigratePersistentStoresAutomaticallyOption)
desc.setOption(true as NSNumber, forKey: NSInferMappingModelAutomaticallyOption)
desc.setOption(true as NSNumber, forKey: "CKSyncCoreDataDebug") // Optional: Debug sync
// Add these critical options for relationship sync
desc.setOption(true as NSNumber, forKey: "NSPersistentStoreCloudKitEnforceRecordExistsKey")
desc.setOption(true as NSNumber, forKey: "NSPersistentStoreCloudKitMaintainReferentialIntegrityKey")
// Add this specific option to force schema update
desc.setOption(true as NSNumber, forKey: "NSPersistentStoreRemoteStoreUseCloudKitSchemaKey")
}
When synchronization happens on CloudKit side, it creates CKRecords: CD_Contact and CD_Location. However for CD_Location it creates the relationship CD_contact as a string and references the CD_Contact. This I thought should have come as REFERENCE On the CD_Contact there is no CD_locations field at all. I do see the relationships being printed on coredata side but it does not come as REFERENCE on cloudkit. Spent over a day on this. Is this normal, what am I doing wrong here? Can someone advise?
Hello 👋,
I encounter the "This model instance was invalidated because its backing data could no longer be found the store" crash with SwiftData. Which from what I understood means I try to access a model after it has been removed from the store (makes sense).
I made a quick sample to reproduce/better understand because there some case(s) I can't figure it out.
Let's take a concrete example, we have Home model and a Home can have many Room(s).
// Sample code
@MainActor
let foo = Foo() // A single reference
let database = Database(modelContainer: sharedModelContainer) // A single reference
@MainActor
class Foo {
// Properties to explicilty keep reference of model(s) for the purpose of the POC
var _homes = [Home]()
var _rooms = [Room]()
func fetch() async {
let homes = await database.fetch().map {
sharedModelContainer.mainContext.model(for: $0) as! Home
}
print(ObjectIdentifier(homes[0]), homes[0].rooms?.map(\.id)) // This will crash here or not.
}
// Same version of a delete function with subtle changes.
// Depending on the one you use calling delete then fetch will result in a crash or not.
// Keep a reference to only homes == NO CRASH
func deleteV1() async {
self._homes = await database.fetch().map {
sharedModelContainer.mainContext.model(for: $0) as! Home
}
await database.delete()
}
// Keep a reference to only rooms == NO CRASH
func deleteV2() async {
self._rooms = await database.fetch().map {
sharedModelContainer.mainContext.model(for: $0) as! Home
}[0].rooms ?? []
await database.delete()
}
// Keep a reference to homes & rooms == CRASH 💥
func deleteV3() async {
self._homes = await database.fetch().map {
sharedModelContainer.mainContext.model(for: $0) as! Home
}
self._rooms = _homes[0].rooms ?? []
// or even only retain reference to rooms that have NOT been deleted 🤔 like here "id: 2" make it crash
// self._rooms = _homes[0].rooms?.filter { r in r.id == "2" } ?? []
await database.delete()
}
}
Calling deleteV() then fetch() will result in a crash or not depending on the scenario.
I guess I understand deleteV1, deleteV2. In those case an unsaved model is served by the model(for:) API and accessing properties later on will resolve correctly. The doc says: "The identified persistent model, if known to the context; otherwise, an unsaved model with its persistentModelID property set to persistentModelID."
But I'm not sure about deleteV3. It seems the ModelContext is kind of "aware" there is still cyclic reference between my models that are retained in my code so it will serve these instances instead when calling model(for:) API ? I see my home still have 4 rooms (instead of 2). So I then try to access rooms that are deleted and it crash. Why of that ? I mean why not returning home with two room like in deleteV1 ?
Because SwiftData heavily rely on CoreData may be I miss a very simple thing here. If someone read this and have a clue for me I would be extremely graceful.
PS:
If someone wants to run it on his machine here's some helpful code:
// Database
let sharedModelContainer: ModelContainer = {
let schema = Schema([
Home.self,
Room.self,
])
let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false)
debugPrint(modelConfiguration.url.absoluteString.replacing("%20", with: "\\ "))
return try! ModelContainer(for: schema, configurations: [modelConfiguration])
}()
extension Database {
static let shared = Database(modelContainer: sharedModelContainer)
}
@ModelActor
actor Database {
func insert() async {
let r1 = Room(id: "1", name: "R1")
let r2 = Room(id: "2", name: "R2")
let r3 = Room(id: "3", name: "R3")
let r4 = Room(id: "4", name: "R4")
let home = Home(id: "1", name: "My Home")
home.rooms = [r1, r2, r3, r4]
modelContext.insert(home)
try! modelContext.save()
}
func fetch() async -> [PersistentIdentifier] {
try! modelContext.fetchIdentifiers(FetchDescriptor<Home>())
}
@MainActor
func delete() async {
let mainContext = sharedModelContainer.mainContext
try! mainContext.delete(
model: Room.self,
where: #Predicate { r in
r.id == "1" || r.id == "4"
}
)
try! mainContext.save()
// 🤔 Calling fetch here seems to solve crash too, force home relationship to be rebuild correctly ?
// let _ = try! sharedModelContainer.mainContext.fetch(FetchDescriptor<Home>())
}
}
// Models
@Model
class Home: Identifiable {
@Attribute(.unique) public var id: String
var name: String
@Relationship(deleteRule: .cascade, inverse: \Room.home)
var rooms: [Room]?
init(id: String, name: String, rooms: [Room]? = nil) {
self.id = id
self.name = name
self.rooms = rooms
}
}
@Model
class Room: Identifiable {
@Attribute(.unique) public var id: String
var name: String
var home: Home?
init(id: String, name: String, home: Home? = nil) {
self.id = id
self.name = name
self.home = home
}
}
Hello,
the last days I was trying to solve a bug in my Unit Tests related to the CoreData "NSManagedObjectContextObjectsDidChange" Notification.
Im using some kind of Notification handler to save and abstract that for the UI and while the tests are running this notification was triggered with objects that doesn't exists anymore, which has resulted in a crash.
After some debugging I have detected, that the objects in here are really old. The objects here was from few tests ago, where a Merge Conflict happened. In the meantime there was a plenty of resets and deletes of the whole db. I have also seen that the bad notification is the first in the stack trace of the main thread, which is in my opinion also not usual.
So the real question is:
The only difference what I have found for the bad notification to the real notification, was the existence of the key "NSObjectsChangedByMergeChangesKey" in the UserInfo dictionary of the ObjectsDidChange Notification. But this key is nowhere found in the documentation of Apple. Also the search engines does not produce any result. So what is this key and when is this key contained in this notification and when not?
Maybe if I understand this, it helps me to understand the overall issue ...
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?
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?
Apple's iCloud File Management documentation says to "avoid special punctuation or other special characters" in filenames, but doesn't specify which characters. I need a definitive list to implement filename sanitization in my shipping app.
Confirmed issues
Our iOS app (CyberTuner, App Store, 15 years shipping on App Store) manages .rcta files in the iCloud ubiquity container via NSFileManager APIs. We've confirmed two characters causing sync failures:
Ampersand (&): A file named Yamaha CP70 & CP80.rcta caused repeated "couldn't be backed up" dialogs. ~12 users reported this independently. Replacing & resolved it immediately. No other files in the same directory were affected.
Percent (%): A file with % in the filename was duplicated by iCloud sync (e.g., filename% 1.rcta, filename% 2.rcta), and the original was lost. Currently reproducing across multiple devices.
Both characters have special meaning in URL encoding (% is the escape character, & is the query parameter separator), which suggests the issue may be in URL handling within the sync pipeline.
What I'm looking for:
A definitive list of characters that cause problems in the iCloud sync pipeline specifically — not APFS restrictions, but CloudDocs/FileProvider/server-side issues.
Confirmation whether these characters are problematic: & % # ? + / : * " < > |
Is there a system API for validating or sanitizing filenames for iCloud compatibility before writing to the ubiquity container?
Our users are piano technicians who naturally name files "Steinway & Sons" — we need to know exactly what to sanitize rather than guessing.
Environment: iOS 17–26, Xcode 26.1, APFS, NSFileManager ubiquity container APIs Bundle FEEDBACK ASSISTANT ID
FB21900837
Topic:
App & System Services
SubTopic:
iCloud & Data
Hi all,
In my SwiftUI / SwiftData / Cloudkit app which is a series of lists, I have a model object called Project which contains an array of model objects called subprojects:
final class Project1
{
var name: String = ""
@Relationship(deleteRule: .cascade, inverse: \Subproject.project) var subprojects : [Subproject]?
init(name: String)
{
self.name = name
self.subprojects = []
}
}
The user will select a project from a list, which will generate a list of subprojects in another list, and if they select a subproject, it will generate a list categories and if the user selects a category it will generate another list of child objects owned by category and on and on.
This is the pattern in my app, I'm constantly passing arrays of model objects that are the children of other model objects throughout the program, and I need the user to be able to add and remove things from them.
My initial approach was to pass these arrays as bindings so that I'd be able to mutate them. This worked for the most part but there were two problems: it was a lot of custom binding code and when I had to unwrap these bindings using init?(_ base: Binding<Value?>), my program would crash if one of these arrays became nil (it's some weird quirk of that init that I don't understand at al).
As I'm still learning the framework, I had not realized that the @model macro had automatically made my model objects observable, so I decided to remove the bindings and simply pass the arrays by reference, and while it seems these references will carry the most up to date version of the array, you cannot mutate them unless you have access to the parent and mutate it like such:
project.subcategories?.removeAll { $0 == subcategory }
project.subcategories?.append(subcategory)
This is weirding me out because you can't unwrap subcategories before you try to mutate the array, it has to be done like above. In my code, I like to unwrap all optionals at the moment that I need the values stored in them and if not, I like to post an error to the user. Isn't that the point of optionals? So I don't understand why it's like this and ultimately am wondering if I'm using the correct design pattern for what I'm trying to accomplish or if I'm missing something? Any input would be much appreciated!
Also, I do have a small MRE project if the explanation above wasn't clear enough, but I was unable to paste in here (too long), attach the zip or paste a link to Google Drive. Open to sharing it if anyone can tell me the best way to do so. Thanks!
We are currently implementing a custom iCloud sync for our macOS and iOS apps using CloudKit. Syncing works fine as long as the number of record sends is relatively small.
But when we test with a large number of changes ( 80,000+ CKRecords ) we start running into problems.
Our sending strategy is very conservative to avoid rate limits:
We send records sequentially in batches of 250 records
With about 2 seconds pause between operations
Records are small and contain no assets (assets are uploaded separately)
At some point we start receiving:
“Database commit size exceeds limit”
After that, CloudKit begins returning rate-limit errors with retryAfter-Information in the error.
We wait for the retry time and try again, but from this moment on, nothing progresses anymore. Every subsequent attempt fails.
We could not find anything in the official documentation regarding such a “commit size” limit or what triggers this failure state.
So my questions are:
Are there undocumented limits on the total number of records that can exist in an iCloud database (private or shared)?
Is there a maximum volume of record modifications a container can accept within a certain timeframe, even if operations are split into small batches with pauses?
Is it possible that sending large numbers of records in a row can temporarily or permanently “stall” a CloudKit container?
Any insights or experiences would be greatly appreciated.
Thank you!
I have the following struct doing some simple tasks, running a network request and then saving items to Core Data.
Per Xcode 26's new default settings (onisolated(nonsending) & defaultIsolation set to MainActor), the struct and its functions run on the main actor, which works fine and I can even safely omit the context.perform call because of it, which is great.
struct DataHandler {
func importGames(withIDs ids: [Int]) async throws {
...
let context = PersistenceController.shared.container.viewContext
for game in games {
let newGame = GYGame(context: context)
newGame.id = UUID()
}
try context.save()
}
}
Now, I want to run this in a background thread to increase performance and responsiveness. So I followed this session (https://developer.apple.com/videos/play/wwdc2025/270) and believe the solution is to mark the struct as nonisolated and the function itself as @concurrent.
The function now works on a background thread, but I receive a crash: _dispatch_assert_queue_fail. This happens whether I wrap the Core Data calls with context.perform or not. Alongside that I get a few new warnings which I have no idea how to work around.
So, what am I doing wrong here? What's the correct way to solve this simple use case with Swift 6's new concurrency stuff and the default main actor isolation in Xcode 26?
Curiously enough, when setting onisolated(nonsending) to false & defaultIsolation to non isolating, mimicking the previous behavior, the function works without crashing.
nonisolated
struct DataHandler {
@concurrent
func importGames(withIDs ids: [Int]) async throws {
...
let context = await PersistenceController.shared.container.newBackgroundContext()
for game in games {
let newGame = GYGame(context: context)
newGame.id = UUID() // Main actor-isolated property 'id' can not be mutated from a nonisolated context; this is an error in the Swift 6 language mode
}
try context.save()
}
}
So i created an App and for some time it was working fine. The app has features to show pdf to users without logging in. I needed to upload all data to cloudkit on public database.
I was not having knowledge that there are 2 mode being a noob in coding so after i saved all records in development mode in cloudkit when i published my app, i was not able to see them (Reason because live mode works in Production mode).
So i need help now to transfer data from development mode to production mode or any app or code that can help me upload all data in production mode.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
CloudKit Dashboard
CloudKit Console
According to my experiments SwiftData does not work with model attributes of primitive type UInt64. More precisely, it crashes in the getter of a UInt64 attribute invoked on an object fetched from the data store.
With Core Data persistent UInt64 attributes are not a problem. Does anyone know whether SwiftData will ever support UInt64?
I am following Apple's instruction to sync SwiftData with CloudKit. While initiating the ModelContainer, right after removing the store from Core Data, the error occurs:
FAULT: NSInternalInconsistencyException: This NSPersistentStoreCoordinator has no persistent stores (unknown). It cannot perform a save operation.; (user info absent)
I've tried removing default.store and its related files/folders before creating the ModelContainer with FileManager but it does not resolve the issue. Isn't it supposed to create a new store when the ModelContainer is initialized? I don't understand why this error occurs. Error disappears when I comment out the #if DEBUG block.
Code:
import CoreData
import SwiftData
import SwiftUI
struct InitView: View {
@Binding var modelContainer: ModelContainer?
@Binding var isReady: Bool
@State private var loadingDots = ""
@State private var timer: Timer?
var body: some View {
VStack(spacing: 16) {
Text("Loading\(loadingDots)")
.font(.title2)
.foregroundColor(.gray)
}
.padding()
.onAppear {
startAnimation()
registerTransformers()
let config = ModelConfiguration()
let newContainer: ModelContainer
do {
#if DEBUG
// Use an autorelease pool to make sure Swift deallocates the persistent
// container before setting up the SwiftData stack.
try autoreleasepool {
let desc = NSPersistentStoreDescription(url: config.url)
let opts = NSPersistentCloudKitContainerOptions(containerIdentifier: "iCloud.my-container-identifier")
desc.cloudKitContainerOptions = opts
// Load the store synchronously so it completes before initializing the
// CloudKit schema.
desc.shouldAddStoreAsynchronously = false
if let mom = NSManagedObjectModel.makeManagedObjectModel(for: [Page.self]) {
let container = NSPersistentCloudKitContainer(name: "Pages", managedObjectModel: mom)
container.persistentStoreDescriptions = [desc]
container.loadPersistentStores { _, err in
if let err {
fatalError(err.localizedDescription)
}
}
// Initialize the CloudKit schema after the store finishes loading.
try container.initializeCloudKitSchema()
// Remove and unload the store from the persistent container.
if let store = container.persistentStoreCoordinator.persistentStores.first {
try container.persistentStoreCoordinator.remove(store)
}
}
// let fileManager = FileManager.default
// let sqliteURL = config.url
// let urls: [URL] = [
// sqliteURL,
// sqliteURL.deletingLastPathComponent().appendingPathComponent("default.store-shm"),
// sqliteURL.deletingLastPathComponent().appendingPathComponent("default.store-wal"),
// sqliteURL.deletingLastPathComponent().appendingPathComponent(".default_SUPPORT"),
// sqliteURL.deletingLastPathComponent().appendingPathComponent("default_ckAssets")
// ]
// for url in urls {
// try? fileManager.removeItem(at: url)
// }
}
#endif
newContainer = try ModelContainer(for: Page.self,
configurations: config) // ERROR!!!
} catch {
fatalError(error.localizedDescription)
}
modelContainer = newContainer
isReady = true
}
.onDisappear {
stopAnimation()
}
}
private func startAnimation() {
timer = Timer.scheduledTimer(
withTimeInterval: 0.5,
repeats: true
) { _ in
updateLoadingDots()
}
}
private func stopAnimation() {
timer?.invalidate()
timer = nil
}
private func updateLoadingDots() {
if loadingDots.count > 2 {
loadingDots = ""
} else {
loadingDots += "."
}
}
}
import CoreData
import SwiftData
import SwiftUI
@main
struct MyApp: App {
@State private var modelContainer: ModelContainer?
@State private var isReady: Bool = false
var body: some Scene {
WindowGroup {
if isReady, let modelContainer = modelContainer {
ContentView()
.modelContainer(modelContainer)
} else {
InitView(modelContainer: $modelContainer, isReady: $isReady)
}
}
}
}
Is there a way to view the data saved when using swiftdata? Even after deleting all models, the storage space taken up by the app in Settings is too large.
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
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
Cloud and Local Storage
CloudKit Console
I've noticed that SwiftData's @Relationship seems to potentially cause application crashes.
The crash error is shown in the image.
Since this crash appears to be random and I cannot reproduce it under specific circumstances, I can only temporarily highlight that this issue seems to exist.
@Model final class TrainInfo {
@Relationship(deleteRule: .cascade, inverse: \StopStation.trainInfo)
var stations: [StopStation]?
}
@Model final class StopStation {
@Relationship
var trainInfo: TrainInfo?
}
/// some View
var origin: StopStationDisplayable? {
if let train = train as? TrainInfo {
return train.stations?.first(where: { $0.isOrigin }) ?? train.stations?.first(where: { $0.isStarting })
}
return nil
}
// Some other function or property
func someFunction() {
if let origin, let destination {
// Function implementation
}
}
About 4 months ago, I shipped the first version of my app with 4 versioned schemas that, unintentionally, had the same versionIdentifier of 1.2.0 in 2 of them:
V1: 1.0.0
V2: 1.1.0
V3: 1.2.0
V4: 1.2.0
They are ordered correctly in the MigrationPlan, and they are all lightweight.
Migration works, SwiftData doesn't crash on init and I haven't encountered any issues related to this. The app syncs with iCloud.
Questions, preferable for anybody with knowledge of SwiftData internals:
What will break in SwiftData when there are 2 duplicate numbers?
Not that I would expect it to be safe, but does it happen to be safe to ship an update that changes V4's version to 1.3.0, what was originally intended?
Topic:
App & System Services
SubTopic:
iCloud & Data
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:
I'm building a photo editing app with a token-based subscription system using RevenueCat and StoreKit. Users purchase subscriptions that grant tokens for AI generations. There are no user accounts, the app is fully anonymous.
Currently, I generate an anonymous account ID via RevenueCat SDK and store it in iCloud Keychain. This allows users on the same iCloud account to restore both their subscription and token balance across devices. However, users on a different iCloud account can restore their subscription via Apple, but their token balance is lost because there's no way to link the anonymous IDs.
The problem is that if a user switches iCloud accounts or gets a new device without the same iCloud, their purchased tokens are orphaned. The subscription restores fine through Apple, but the token balance tied to the old anonymous ID becomes inaccessible.
I have a few constraints: no user accounts, no email or phone sign-in, must work across devices owned by the same person, and must comply with App Store guidelines.
My questions are: Is iCloud Keychain the right tool for this, or is there a better approach? Would CloudKit with an anonymous record zone be more appropriate? Are there any recommended patterns for persisting consumable balances tied to anonymous users across device migrations?
Any guidance would be appreciated.
Topic:
App & System Services
SubTopic:
iCloud & Data