SwiftData error on iOS 18, Never access a full future backing data

Question

Try to update my app from iOS 17 to iOS 18. I'm using SwiftData to save the data on the memory. On iOS 17 all works fine, but I tried to export my app to iOS 18, and I get a strange error when I try to delete a playlist from SwiftData memory.

Thread 10: Fatal error: Never access a full future backing data - PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: x-coredata://4885953A-BDB2-4CD1-9299-B2FBBB899EB7/PlaylistItem/p372), implementation: SwiftData.PersistentIdentifierImplementation) with Optional(B2A80504-2FE1-4C86-8341-3DDE8B6AB913)

The code where this error happen is very simple,

  func deletePlaylist(_ playlist: PlayListModel) async throws {
        print("attempt to delate :, \(playlist.playlistName)")
        context.delete(playlist)
        try context.save() // error here on the save 
    }

Error only happen on iOS 18 not on the 17.

Answer 1

I had the error too, no iCloud, iOS 18 beta 2. What fixed it for me is deleting all relationships and saving the context before I delete the parent.

for parent in parentsToDelete {
    for child in parent.childs {
        context.delete(child)
    }
    try context.save()
    context.delete(parent)
}
try context.save()