I'm running a project with these settings:
Default Actor Isolation: MainActor
Approachable Concurrency: Yes
Strict Concurrency Checking: Complete (this issue does not appear on the other two modes)
I receive a warning for this very simple use case. Can I actually fix anything about this or is this a case of Core Data not being entirely ready for this?
In reference to this, there was a workaround listed in the release notes of iOS 26 beta 5 (https://forums.swift.org/t/defaultisolation-mainactor-and-core-data-background-tasks/80569/22). Does this still apply as the only fix for this?
This is a simplified sample meant to run on a background context. The issue obviously goes away if this function would just run on the MainActor, then I can remove the perform block entirely.
class DataHandler {
func createItem() async {
let context = ...
await context.perform {
let newGame = Item(context: context)
/// Main actor-isolated property 'timestamp' can not be mutated from a Sendable closure
newGame.timestamp = Date.now
// ...
}
}
}
The complete use case would be more like this:
nonisolated
struct DataHandler {
@concurrent
func saveItem() async throws {
let context = await PersistenceController.shared.container.newBackgroundContext()
try await context.perform {
let newGame = Item(context: context)
newGame.timestamp = Date.now
try context.save()
}
}
}
2
1
541