Core Data in XCFramework

I am trying to create a XCFramework with the functionality of core data.

I simplly create a xcdatamodel and one entity in it.

Something like this:

@objc(Conversation)
public class Conversation: NSManagedObject {

}

extension Conversation {

    @nonobjc public class func fetchRequest() -> NSFetchRequest {
        return NSFetchRequest(entityName: "Conversation")
    }

    @NSManaged public var message: String?
    @NSManaged public var date: Date?

}

} 

When I create the XCFramework, it won't compile in the host app.

(I create the XCFramework by using the xcodebuild -create-xcframework)

The error is :

@NSManaged not allowed on computed properties

In the swiftInterface I got something like this:

@objc(Conversation) public class Conversation : CoreData.NSManagedObject {
  @objc override dynamic public init(entity: CoreData.NSEntityDescription, insertInto context: CoreData.NSManagedObjectContext?)
  @objc deinit
}
extension Conversation {
  @nonobjc public class func fetchRequest() -> CoreData.NSFetchRequest<xcframeworktest.Conversation>
  @objc @NSManaged dynamic public var date: Foundation.Date? {
    @objc get
    @objc set
  }
  @objc @NSManaged dynamic public var message: Swift.String? {
    @objc get
    @objc set
  }
}

My question is: How to not generate the getter and setter for NSManaged attributes when creating the XCFramework?