I'm seeing the same issue. As a workaround I've manually added the conformance to Identifiable to the model: extension MyModel: Identifiable { public var id: PersistentIdentifier { persistentModelID } }

The only thing I see different to a migration I have working is that the versionIdentifier seems to have changed in Beta 5 to a non-optional string (the docs don't seem to have caught up). I've set them to a string of my choosing: static var versionIdentifier: String = "V1"

In my unit tests, I need to insert Foo into a context before I can set the relationship to Bar. If the parent entity does not have a context I see a crash in the getter. let foo = Foo(bar: []) container.mainContext.insert(foo) foo.append(bar: Bar(value: 0)) You will need to mark the test as running on the MainActor to access the mainContext.

I'm still seeing this in iOS 16.1 (FB11826112)

It looks like your trying to load the model from the main bundle. You need to load it from the Swift package bundle and then pass it to the NSPersistentContainer initializer.