My project is using swiftData and I want to implement iCloud sync in it. Now, my data base doesnt have any optional attributes or relationships and CloudKit wants them to be optional. So, rather than editing all code with unwrapping code for the optionals, how can I provide a bridge that does so in the last stage of actually saving to the store? Sort of, capture it in a proxy object before writing and after reading from the store. Is there a neat way that can save a lot of debugging? I have code snippets from chat gpt and they are hard to debug. This is my first project in swiftUI. Thanks. Neerav

I have a strange crash which I have problems understanding. It only happens on a few devices, after a ModelContainer migration, and it doesn't seem to crash on the migration itself. The fetch is done in onAppear, and shouldn't necessarily result in a crash, as it is an optional try: let request = FetchDescriptor<Rifle>() let data = try? modelContext.fetch(request) if let data, !data.isEmpty { rifle = data.first(where: { $0.uuid.uuidString == settings.selectedRifleId }) ?? data.first! } When I get logs from users, there seems to be an error in encoding? Exception Type: EXC_BREAKPOINT (SIGTRAP) Exception Codes: 0x0000000000000001, 0x000000018e8bfd78 Termination Reason: ****** 5 Trace/BPT trap: 5 Terminating Process: exc handler [71687] Triggered by Thread: 0 Thread 0 name: Dispatch queue: com.apple.main-thread Thread 0 Crashed: 0 libswiftCore.dylib 0x18e8bfd78 _assertionFailure(_:_:file:line:flags:) + 264 1 SwiftData 0x24e18b480 0x24e14c000 + 259200 2 SwiftData 0x24e193968 0x24e14c000 + 293224 3 SwiftData 0x24e195a78 0x24e14c000 + 301688 4 libswiftCore.dylib 0x18e8e4084 _KeyedEncodingContainerBox.encodeNil<A>(forKey:) + 352 5 libswiftCore.dylib 0x18e8d79f0 KeyedEncodingContainer.encodeNil(forKey:) + 64 6 SwiftData 0x24e19f09c 0x24e14c000 + 340124 7 SwiftData 0x24e1a3dec 0x24e14c000 + 359916 8 libswiftCore.dylib 0x18ec10be8 dispatch thunk of Encodable.encode(to:) + 32 9 SwiftData 0x24e1cd500 0x24e14c000 + 529664 10 SwiftData 0x24e1cd0c8 0x24e14c000 + 528584 11 SwiftData 0x24e1da960 0x24e14c000 + 584032 12 SwiftData 0x24e1ee2ec 0x24e14c000 + 664300 13 SwiftData 0x24e1d97d8 0x24e14c000 + 579544 14 SwiftData 0x24e1eada0 0x24e14c000 + 650656 15 SwiftData 0x24e1d989c 0x24e14c000 + 579740 16 SwiftData 0x24e1eee78 0x24e14c000 + 667256 17 Impact 0x1027403bc 0x10268c000 + 738236

Hello, thank you Apple for supporting custom store with SwiftData and the Schema type is superb to work with. I have successfully set one up with SQL and have some feedback and issues regarding its APIs. There’s a highlighted message in the documentation about not using internal restricted symbols directly, but they contradict with the given protocols and I am concerned about breaking any App Store rules. Are we allowed to use these? If not, they should be opened up as they’re useful. BackingData is required to set up custom snapshots, initialization, and getting/setting values. And I want to use it with createBackingData() to directly initialize instances from snapshots when transferring them between server and client or concurrency. RelationshipCollection for casting to-many relationships from backing data or checking if an array contains a PersistentModel. SchemaProperty for type erasure in a collection. Schema.Relationship has KeyPath properties, but it is missing for Schema.Attribute and Schema.CompositeAttribute. Which means you can’t purely depend on the schema to map data. I am unable to access the properties of a custom struct type in a predicate unless I use Mirror with schemaMetadata() or CustomStringConvertible on the KeyPath directly to extract it. Trivial, but… the KeyPath property name is inconsistent (it’s all lowercase). It would be nice to retrieve property names from custom struct types, since you are unable access CodingKeys that are auto synthesized by Codable for structs. But I recently realized they’re a part Schema.CompositeAttribute, however I don’t know how to match these without the KeyPath… I currently map my entities using CodingKeys to their PredicateCodableKeyPathProviding.… but I wish for a simpler alternative! It’s unclear how to provide the schema to the snapshot before new models are created. I currently use a static property, but I want to make it flexible if more schemas and configurations are added later on. I considered saving and loading the schema in a temporary location, but doubtful that the KeyPath values will be available as they are not Codable. I suspect schemaMetadata() has the information I need to map the backing data without a schema for snapshots, but as mentioned previously, properties are inaccessible… Allow access to entity metatypes, like value types from SchemaProperty. They’re useful for getting data out of snapshots and casting them to CodingKeys and PredicateCodableKeyPathProviding. They do not carry over when you provide them in the Schema. I am unable to retrieve the primary key from PersistentIdentifier. It seems like once you create one, you can’t get it out, like the DataStoreConfiguration in ModelContainer is not the one you used to set it up. I cannot cast it, it is an entirely different struct? I have to use JSONSerialization to extract it, but I want to get it directly since it is not a column in my database. It is transformed when it goes to/from my tables. It’s unknown how to support some schema options, such as Spotlight and CloudKit. Allow for extending macro options, such as adding options to set as primary key, whether to auto increment, etc… You can create a schema for super and sub entities, but it doesn’t appear you can actually set them up from the @Model macro or use inheritance on these models… SwiftData history tracking seems incomplete for HistoryDelete, because that protocol requires HistoryTombstone, but this type cannot be instantiated, nor does it contain anything useful to infer from. As an aside, I want to create my own custom ModelActor that is a global actor. However, I’m unable to replicate the executor that Apple provides where the executor has a ModelContext, because this type does not conform to Sendable. So how did Apple do this? The documentation doesn’t mention unchecked Sendable, but I figure if the protocol is available then we would be able to set up our own. And please add concurrency features! Anyway, I hope for more continued support in the future and I am looking forward to what’s new this WWDC! 😊

Hi, I am developing a Screen Time App and I am having issues with the ShieldConfigurationExtension (ShieldConfigurationDataSource). I know this extensions is sandboxed but I should be able to read data from the main app. I am using SwiftData as my database, but I am unable to initialize it in the extensions with an error indicating insufficient file permissions. I have App Group set up and I am able to share data using UserDefaults but that is just inconvenient. Is there any way I could just open the SwiftData in read only mode so that I could display the user some info on the shield? SwiftData Init: private func setupContainer() throws { let schema = Schema([ DogEntity.self, HouseEntity.self ]) // Use app group container if available let config: ModelConfiguration if let containerURL = FileManager.default.containerURL( forSecurityApplicationGroupIdentifier: "group.\(Bundle.app.bundleIdentifier ?? "")" ) { config = ModelConfiguration(schema: schema, url: containerURL.appendingPathComponent("default.sqlite")) } else { config = ModelConfiguration(schema: schema) } self.container = try ModelContainer(for: schema, configurations: [config]) } Error in extension: fault: Attempt to add read-only file at path file:///private/var/mobile/Containers/Shared/AppGroup/51431199-5919-4AE6-940C-6FE3C53EEB46/default.sqlite read/write. Adding it read-only instead. This will be a hard error in the future; you must specify the NSReadOnlyPersistentStoreOption. error: (3) access permission denied error: Encountered exception error during prepareSQL for SQL string 'SELECT TBL_NAME FROM SQLITE_MASTER WHERE TBL_NAME = 'Z_METADATA'' : access permission denied with userInfo { NSFilePath = "/private/var/mobile/Containers/Shared/AppGroup/51431199-5919-4AE6-940C-6FE3C53EEB46/default.sqlite"; NSSQLiteErrorDomain = 3; } while checking table name from store: <NSSQLiteConnection: 0x154100300> error: Store failed to load. <NSPersistentStoreDescription: 0x15402d590> (type: SQLite, url: file:///private/var/mobile/Containers/Shared/AppGroup/51431199-5919-4AE6-940C-6FE3C53EEB46/default.sqlite) with error = Error Domain=NSCocoaErrorDomain Code=256 "The file “default.sqlite” couldn’t be opened." UserInfo={NSFilePath=/private/var/mobile/Containers/Shared/AppGroup/51431199-5919-4AE6-940C-6FE3C53EEB46/default.sqlite, NSSQLiteErrorDomain=3} with userInfo { NSFilePath = "/private/var/mobile/Containers/Shared/AppGroup/51431199-5919-4AE6-940C-6FE3C53EEB46/default.sqlite"; NSSQLiteErrorDomain = 3; } Any help appreciated 🙂

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) } } } }

I'm running into a crash when trying to delete an item from a list that's loaded using SwiftData. The app works fine when selecting or displaying the data, but the moment I confirm a deletion, it crashes with this error: SwiftData/ModelSnapshot.swift:46: Fatal error: A ModelSnapshot must be initialized with a known-keys dictionary This happens right after I delete an item from the list using modelContext.delete(). I’ve double-checked that the item exists and is valid, and I'm not sure what I'm doing wrong. The data is loaded using @Query and everything seems normal until deletion. For further information, I have tried this on a new IOS project where I have one super Model class with a cascading relationship on a child class. When trying to delete the parent class while connected to one or more children, it still gives me the error. The same thing is happening with my original project. Class A has a relationship (cascading) with Class B. Attempting to delete Class A while there are relationships with Class B throws this error. If anyone has experienced this or knows what causes it, please let me know. I’m not even sure where to start debugging this one. Thanks in advance!

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).

Hi all, I’m encountering a consistent issue with SwiftData on watchOS when using CloudKit sync. After enabling: let config = ModelConfiguration(schema: schema, cloudKitDatabase: .automatic) …the app terminates ~30–60 seconds into a WKExtendedRuntimeSession. This happens specifically when: Always-On Display is OFF The iPhone is disconnected or in Airplane Mode The app is running in a WKExtendedRuntimeSession (e.g., used for meditation tracking) The Xcode logs show a warning: Background Task ("CoreData: CloudKit Setup"), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination. It appears CloudKit sync setup is being triggered automatically and flagged by the system as an unmanaged long-running task, leading to termination. Workaround: Switching to: let config = ModelConfiguration(schema: schema, cloudKitDatabase: .none) …prevents the issue entirely — no background task warning, no crash. Feedback ID submitted: FB17685611 Just wanted to check if others have seen this behavior or found alternative solutions. It seems like something Apple may need to address in SwiftData’s CloudKit handling on watchOS.

I'm seeing a lot of these in my logs: PersistentIdentifier PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: x-swiftdata://Course/BC9CF99A-DE6A-46F1-A18D-8034255A56D8), implementation: SwiftData.PersistentIdentifierImplementation) was remapped to a temporary identifier during save: PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: x-coredata:///Course/t58C849CD-D895-4773-BF53-3F63CF48935B210), implementation: SwiftData.PersistentIdentifierImplementation). This is a fatal logic error in DefaultStore ... though everything seems to work. Does anyone know what this means in this context? Anything I can do to not have this appear?

Issue with SwiftData: “no such table: ZAPPSETTINGS” and SQLite I/O error on app launch Hello, I’m encountering persistent errors with SwiftData in my SwiftUI app related to Core Data’s underlying SQLite database. Despite defining my models correctly, the app fails to initialize the persistent store, throwing the following error on startup: CoreData error: SQLCore dispatchRequest: no such table: ZAPPSETTINGS. I/O error opening database at /.../default.store. SQLite error code:1, NSSQLiteErrorDomain=1. File “default.store” couldn’t be opened. Context The error only appears concerning my AppSettings model. I have another model, LocationPoint, which appears correctly defined and used. I have tried deleting the app, resetting the device, and cleaning builds but the error persists. The error message suggests the database file is present but the table for ZAPPSETTINGS (the Core Data table for AppSettings) does not exist. Code Samples Main App Entry import SwiftData import SwiftUI @main struct Krow3_0App: App { @State private var userLocationManager = UserLocationManager() @State private var geocodingViewModel = GeocodingViewModel() @State private var locationSearchViewModel = LocationSearchViewModel() @State private var router = Router() var body: some Scene { WindowGroup { LaunchView() .environment(userLocationManager) .environment(geocodingViewModel) .environment(locationSearchViewModel) .environment(router) .modelContainer(for: [LocationPoint.self, AppSettings.self]) } } } AppSettings Model import Foundation import SwiftData @Model class AppSettings { var isMetric: Bool init(isMetric: Bool = false) { self.isMetric = isMetric } } What I’ve Tried Fully uninstalling and reinstalling the app on device and simulator. Resetting the simulator/device. Cleaning the Xcode build folder. Verifying the schema logs which correctly list both LocationPoint and AppSettings. Changing model names to avoid potential conflicts. Adding .modelContainer configuration with autosave enabled. Questions Is there a known bug or limitation with SwiftData concerning certain model setups or naming? Could this be related to how the data container initializes or migrates schemas? Are there recommended debugging or migration steps to resolve “no such table” SQLite errors with SwiftData? How can I safely reset or migrate the persistent store without corrupting the database? Any insights or suggestions would be greatly appreciated! Thank you!

I have an issue in my app, where the crashing frame is an assertionFailure in BackingData.set inside SwiftData framework. My own app doesn't appear until frame 14. I have no idea what causes this, or even how to create a reproducible project as this only happens on some devices. The frame prior to the assertionFailure is this: #1 (null) in BackingData.set(any:value:) () It seems like there is a backing data encoding happening in my Model class, and some value is causing it to fail. The model being accessed is through a relationship, and the frame in the app crashing is along the lines of Text(parent.child.name) Obviously, something is wrong in how I have made child, but the part that stand out to me is the assertionFailure in a release build

I'm writing some tests to confirm the behavior of my app. White creating a model actor to delete objects I realized that ModelContext.model(for:) does return objects that are deleted. I was able to reproduces this with this minimal test case: @Model class Activity { init() {} } struct MyLibraryTests { let modelContainer = try! ModelContainer( for: Activity.self, configurations: ModelConfiguration( isStoredInMemoryOnly: true ) ) init() throws { let context = ModelContext(modelContainer) context.insert(Activity()) try context.save() } @Test func modelForIdAfterDelete() async throws { let context = ModelContext(modelContainer) let id = try context.fetch(FetchDescriptor<Activity>()).first!.id context.delete(context.model(for: id) as! Activity) try context.save() let result = context.model(for: id) as? Activity #expect(result == nil) // Expectation failed: (result → MyLibrary.Activity) == nil } @Test func fetchDescriptorAfterDelete() async throws { let context = ModelContext(modelContainer) let id = try context.fetch(FetchDescriptor<Activity>()).first!.id context.delete(context.model(for: id) as! Activity) try context.save() let result = try context.fetch( FetchDescriptor<Activity>(predicate: #Predicate { $0.id == id }) ).first #expect(result == nil) } } Here I create a new context, insert an model and save it. The test modelForIdAfterDelete does fail, as result still contains the deleted object. I also tried to check #expect(result!.isDeleted), but it is also false. With the second test I use a FetchDescriptor to retrieve the object by ID and it correctly returns nil. Shouldn't both methods use a consistent behavior?

Problem The following code doesn't work: let predicate = #Predicate<Car> { car in car.size == size //This doesn't work } Console Error Query encountered an error: SwiftData.SwiftDataError(_error: SwiftData.SwiftDataError._Error.unsupportedPredicate) Root cause Size is an enum, #Predicate works with other type such as String however doesn't work with enum Enum value is saved however is not filtered by #Predicate Environment Xcode: 15.0 (15A240d) - App Store macOS: 14.0 (23A339) - Release Candidate Steps to reproduce Run the app on iOS 17 or macOS Sonoma Press the Add button Notice that the list remains empty Expected behaviour List should show the newly created small car Actual behaviour List remains empty inspite of successfully creating the small car. Feedback FB13194334 Code Size enum Size: String, Codable { case small case medium case large } Car import SwiftData @Model class Car { let id: UUID let name: String let size: Size init( id: UUID, name: String, size: Size ) { self.id = id self.name = name self.size = size } } ContentView struct ContentView: View { var body: some View { NavigationStack { CarList(size: .small) } } CarList import SwiftUI import SwiftData struct CarList: View { let size: Size @Environment(\.modelContext) private var modelContext @Query private var cars: [Car] init(size: Size) { self.size = size let predicate = #Predicate<Car> { car in car.size == size //This doesn't work } _cars = Query(filter: predicate, sort: \.name) } var body: some View { List(cars) { car in VStack(alignment: .leading) { Text(car.name) Text("\(car.size.rawValue)") Text(car.id.uuidString) .font(.footnote) } } .toolbar { Button("Add") { createCar() } } } private func createCar() { let name = "aaa" let car = Car( id: UUID(), name: name, size: size ) modelContext.insert(car) } }

Hi ! Would anyone know (if possible) how to create backup files to export and then import from the data recorded by SwiftData? For those who wish, here is a more detailed explanation of my case: I am developing a small management software with customers and events represented by distinct classes. I would like to have an "Export" button to create a file with all the instances of these 2 classes and another "Import" button to replace all the old data with the new ones from a previously exported file. I looked for several solutions but I'm a little lost...

I'm using SwiftData with CloutKit with a very simple app. Data syncs between iOS, iPadOS, and visionOS, but not macOS. From what I can tell, macOS is never getting CK messages unless I'm running the app from Xcode. I can listen for the CK messages and show a line in a debug overlay. This works perfectly when I run from Xcode. I can see the notifications and see updates in my app. However, if I just launch the app outside of Xcode I will never see any changes or notifications. It is as if the Mac app never even tries to contact CloudKit. Schema has been deployed in the CloudKit console. The app is based on the multi-platform Xcode template. Again, only the macOS version has this issue. Is there some extra permission or setting I need to set up in order to use CloudKit on macOS? @State private var publisher = NotificationCenter.default.publisher(for: NSPersistentCloudKitContainer.eventChangedNotification).receive(on: DispatchQueue.main) .onReceive(publisher) { notification in // Listen for changes in CK events if let userInfo = notification.userInfo, let event = userInfo[NSPersistentCloudKitContainer.eventNotificationUserInfoKey] as? NSPersistentCloudKitContainer.Event { let message = "CloudKit Sync: \(event.type.rawValue) - \(event.succeeded ? "Success" : "Failed") - \(event.description)" // Store for UI display syncNotifications.append(message) if syncNotifications.count > 10 { syncNotifications.removeFirst() } } } .overlay(alignment: .topTrailing) { if !syncNotifications.isEmpty { VStack(alignment: .leading) { ForEach(syncNotifications, id: \.self) { notification in Text(notification) .padding(8) } } .frame(width: 800, height: 500) .cornerRadius(8) .background(Color.secondary.opacity(0.2)) .padding() .transition(.move(edge: .top)) } }

I have a SwiftData document-based app. It is initialized like this: @main struct MyApp: App { @State private var showTemplatePicker = false @State private var documentCreationContinuation: CheckedContinuation<URL?, any Error>? var body: some Scene { DocumentGroup(editing: .myDocument, migrationPlan: MyMigrationPlan.self) { CanvasView() } DocumentGroupLaunchScene(Text("My App")) { NewDocumentButton("New", contentType: .canvasDocument) { try await withCheckedThrowingContinuation { continuation in documentCreationContinuation = continuation showTemplatePicker = true } } .fullScreenCover(isPresented: $showTemplatePicker) { TemplateView(documentCreationContinuation: $documentCreationContinuation) } } background: { Image("BoardVignette") .resizable() } } } extension UTType { static var canvasDocument: UTType { UTType(importedAs: "com.example.MyApp.canvas") } } Pressing the New button crashes with: #0 0x00000001d3a6e12c in (1) suspend resume partial function for closure #1 () async -> () in SwiftUI.IdentifiedDocumentGroupDocumentCreation.createNewDocument(with: SwiftUI.IdentifiedDocumentGroupConfiguration, url: Swift.Optional<Foundation.URL>, newDocumentProvider: Swift.Optional<SwiftUI.AsyncNewDocumentProvider>, _: (Swift.Optional<SwiftUI.PlatformDocument>) -> ()) -> () () All sample code that I've seen uses a FileDocument but SwiftData's setup doesn't have one so it's not completely clear how you should be using NewDocumentButton with a SwiftData file. The crash happens even before my prepareDocumentURL handler is called (I set a breakpoint and it never stops). My hunch is that the crash is because it's not able to match my contentType to a Document. Can anyone at Apple help? I don't think this use-case has been documented well.

SwiftData crashes 100% when fetching history of a model that contains an optional codable property that's updated: SwiftData/Schema.swift:389: Fatal error: Failed to materialize a keypath for someCodableID.someID from CrashModel. It is possible that this path traverses a type that does not work with append(), please file a bug report with a test. Would really appreciate some help or even a workaround. Code: import Foundation import SwiftData import Testing struct VaultsSwiftDataKnownIssuesTests { @Test func testCodableCrashInHistoryFetch() async throws { let container = try ModelContainer( for: CrashModel.self, configurations: .init( isStoredInMemoryOnly: true ) ) let context = ModelContext(container) try SimpleHistoryChecker.hasLocalHistoryChanges(context: context) // 1: insert a new value and save let model = CrashModel() model.someCodableID = SomeCodableID(someID: "testid1") context.insert(model) try context.save() // 2: check history it's fine. try SimpleHistoryChecker.hasLocalHistoryChanges(context: context) // 3: update the inserted value before then save model.someCodableID = SomeCodableID(someID: "testid2") try context.save() // The next check will always crash on fetchHistory with this error: /* SwiftData/Schema.swift:389: Fatal error: Failed to materialize a keypath for someCodableID.someID from CrashModel. It is possible that this path traverses a type that does not work with append(), please file a bug report with a test. */ try SimpleHistoryChecker.hasLocalHistoryChanges(context: context) } } @Model final class CrashModel { // optional codable crashes. var someCodableID: SomeCodableID? // these actually work: //var someCodableID: SomeCodableID //var someCodableID: [SomeCodableID] init() {} } public struct SomeCodableID: Codable { public let someID: String } final class SimpleHistoryChecker { static func hasLocalHistoryChanges(context: ModelContext) throws { let descriptor = HistoryDescriptor<DefaultHistoryTransaction>() let history = try context.fetchHistory(descriptor) guard let last = history.last else { return } print(last) } }

I am using SwiftData for storage and have a view that uses the @Query property wrapper with a sort descriptor that points to a relationship on a model. In a release build on device running iOS 18.3, the app crashes. This is the line that crashes: @Query(sort: \Item.info.endDate, order: .reverse) private var items: [Item] Item has a relationship to ItemInfo, which is where the endDate property is defined. This code works in debug and on a simulator. In the project referenced here: https://github.com/lepolt/swiftdata-crash, change the scheme build configuration to “Release” and run on device. The app will crash. Using Xcode Version 16.2 (16C5032a) iPhone 12, iOS 18.3 (22D60)

I'm trying out putting most of my business logic in a Protocol that my @Model can conform to, but I'm running into a SwiftUI problem with a Binding that does not get magically offered up like it does when it the subview is not generic. I have a pretty basic List with a ForEach that now can't properly pass to a generic view based on a protocol. When I try to make a binding manually in the row it says that "item is immutable"... but that also doesn't help me with the NavigationLink? Which is seeing the Binding not the ? But before when the subview was concrete to Thing, it took in the and made its own Binding once it hit the view. I'm unclear on precisely where the change happens and what I can do to work around it. Before I go rearchitecting everything... is there a fix to get the NavigationLink to take on the object like before? What needs to be different? I've tried a number of crazy inits on the subview and they all seem to come back to saying either it can't figure out how to pass the type or I'm trying to use the value before it's been initialized. Have I characterized the problem correctly? Thanks! (let me know if I forgot a piece of code, but this should be the List, the Model/Protocol and the subview) import SwiftUI import SwiftData struct ThingsView: View {     @Environment(\.modelContext) var modelContext     @Query var items: [Thing]          var body: some View {         NavigationStack {             List {                 ForEach(items) { item in                     NavigationLink(value: item) {                         VStack(alignment: .leading) {                             Text(item.textInfo)                                 .font(.headline)                                                          Text(item.timestamp.formatted(date: .long, time: .shortened))                         }                     }                 }.onDelete(perform: deleteItems)             }             .navigationTitle("Fliiiing!") //PROBLEM HERE: Cannot convert value of type '(Binding<Thing>) -> EditThingableView<Thing>' to expected argument type '(Thing) -> EditThingableView<Thing>'             .navigationDestination(for: Thing.self, destination: EditThingableView<Thing>.init) #if os(macOS)             .navigationSplitViewColumnWidth(min: 180, ideal: 200) #endif             .toolbar { #if os(iOS)                 ToolbarItem(placement: .navigationBarTrailing) {                     EditButton()                                      } #endif                 ToolbarItem {                     Button(action: addItem) {                         Label("Add Item", systemImage: "plus")                     }                 }                 ToolbarItem {                     Button("Add Samples", action: addSamples)                 }             }         }     }          func addSamples() {         withAnimation {             ItemSDMC.addSamples(context: modelContext)         }     }          private func addItem() {         withAnimation {             let newItem = ItemSDMC("I did a thing!")             modelContext.insert(newItem)         }     }          func deleteItems(_ indexSet:IndexSet) {         withAnimation {             for index in indexSet {                 items[index].delete(from: modelContext)             }         }     } } #Preview {     ThingsView().modelContainer(for: ItemSDMC.self, inMemory: true) } import Foundation import SwiftData protocol Thingable:Identifiable {     var textInfo:String { get set }     var timestamp:Date { get set } } extension Thingable {     var thingDisplay:String {         "\(textInfo) with \(id) at \(timestamp.formatted(date: .long, time: .shortened))"     } } extension Thingable where Self:PersistentModel {     var thingDisplayWithID:String {         "\(textInfo) with modelID \(self.persistentModelID.id) in \(String(describing: self.persistentModelID.storeIdentifier)) at \(timestamp.formatted(date: .long, time: .shortened))"     } } struct ThingLite:Thingable, Codable, Sendable {     var textInfo: String     var timestamp: Date     var id: Int } @Model final class Thing:Thingable {     //using this default value requires writng some clean up logic looking for empty text info.     var textInfo:String = ""     //using this default value would require writing some data clean up functions looking for out of bound dates.     var timestamp:Date = Date.distantPast          init(textInfo: String, timestamp: Date) {         self.textInfo = textInfo         self.timestamp = timestamp     } } extension Thing {     var LiteThing:ThingLite {         ThingLite(textInfo: textInfo, timestamp: timestamp, id: persistentModelID.hashValue)     } } import SwiftUI struct EditThingableView<DisplayItemType:Thingable>: View {     @Binding var thingHolder: DisplayItemType          var body: some View {                  VStack {             Text(thingHolder.thingDisplay)             Form {                 TextField("text", text:$thingHolder.textInfo)                 DatePicker("Date", selection: $thingHolder.timestamp)             }                      } #if os(iOS)         .navigationTitle("Edit Item")         .navigationBarTitleDisplayMode(.inline) #endif     } } //NOTE: First sign of trouble //#Preview { //    @Previewable var myItem = Thing(textInfo: "Example Item for Preview", timestamp:Date()) //    EditThingableView<Thing>(thingHolder: myItem) //}

I'm getting the following error message when executing the rollback method in a modelContext, what could be causing this ? SwiftData/ModelSnapshot.swift:46: Fatal error: A ModelSnapshot must be initialized with a known-keys dictionary