EDIT: As of XCode Beta 7, you need to add the default value back in.Original Post:
I upgraded to Xcode 15 Beta 6, and found some new errors in my SwiftData Project.
On my @Relationship macros, using .cascade, I now have the error “Type ‘PropertyOptions’ has no member ‘cascade’”
We need to add deleteRule: .cascade instead.
But now we see a new error. “Variable ‘self._$backingData’ used before being initialized”
We can no longer set default values where we declare the variables. Removing the =  takes care of the error. (And I did not need to add it to the initializer.)
Final, working code: