fatbobman（东坡肘子）Mar 4

In Swift 6.2 (Xcode 26.3), why can `NSManagedObjectContext` cross actor isolation?

I dug through the Core Data headers to find the real reason—here it is.
https://fatbobman.com/en/posts/sendable-nsmanagedobjectcontext/

Why Does Passing NSManagedObjectContext Across Isolation Domains No Longer Error in Swift 6.2? The Real Change Isn't in the Compiler

Why NSManagedObjectContext no longer triggers concurrency errors in Swift 6.2? The real change lies in Core Data’s SDK import semantics, not the compiler itself. NSManagedObjectContext is now marked with NS_SWIFT_SENDABLE and NS_SWIFT_NONISOLATED in Xcode 26

fatbobman.com
Show threadHelge HeßMar 4
@fatbobman That’s really weird though, isn’t it? I wonder what prompted them to mark the context as Sendable, it’s the exact opposite of that?
Show threadfatbobman（东坡肘子）
@helge I think maybe when building swiftdata, Apple finds that it is necessary to pass context in some specific scenarios. This is the only thing I can think of. Just like in my test code, allowing cross for a special purpose will greatly simplify the implementation. However, I think Apple certainly doesn't want others to pass contex across domains in production. 😂
Mar 4 at 1:04pmWeb
Show threadHelge HeßMar 4
@fatbobman Yup, either it’s a mistake/bug or a hack 🙃