NSPersistentCloudKitContainer

I am trying to build a very basic app using Core Data and CloudKit. I am logged into my CloudKit account on my Mac, and I followed the instructions to run the sample project that Apple provided on their website.Using the sample project as a guide, I tried to build a simpler app using the instructions provided here.However, after building trying to run my sample project, I get the following error stack trace in my console:CoreData: debug: CoreData+CloudKit: -[PFCloudKitOptionsValidator validateOptions:andStoreOptions:error:](35): Validating options: <NSCloudKitMirroringDelegateOptions: 0x60000097f960> containerIdentifier:iCloud.com.cybermedia.CloudKitTest1 initializeSchema:YES ckAssetThresholdBytes:<null> operationMemoryThresholdBytes:<null> useEncryptedStorage:NO automaticallyDownloadFileBackedFutures:NO automaticallyScheduleImportAndExportOperations:YES skipCloudKitSetup:NO preserveLegacyRecordMetadataBehavior:NO useDaemon:YES apsConnectionMachServiceName:<null> containerProvider:<

I added a new Core Data model version, introducing a new entity. Based on the naming of the Entity I get different behaviour: A: If the entity is alphabetically ordered as last entity: Everything works fine. B: There entity is ordered before already existing entities: All records of these existing entities get a new CloudKit id. Resulting in duplicated data and broken relations. In some cases the seem-to-be new insert of these records causes the migration to fail. (Constraint unique violation, reason=constraint violation during attempted migration) My only workaround so far is to just give the entity a different name, to appear last in the list. __ Does anyone else experience this issues? I am not sure if my code could be able to trigger this kind of behaviour. I will try to reproduce it in an empty project, to file a bug report.

What is the expected / best strategy to migrate a synced Core Data model to a new version? The issue: A new app version with a new Core Data model introducing new attributes or entities. DeviceA installs the update and edits data with new values and creates new entities. DeviceB is still used and downloads these changes. The unknown attributes and entities are ignored, but the HistoryTracking gets updated. A few days later DeviceB gets the update. The missing attributes and entities are not downloaded, as the history is up to date. __ The issue exists with iOS 13, I hoped for iOS 14 to introduce a strategy. I tried with the first iOS 14 beta, but it is at least not handled automatically. From the visible API changes I don't see a way to handle this specifically. Not sure if the talks will reveal anything about it. Will apply for a lab session and would like to get as much input to prepare before that might take place.