Rakudo now dies with a typed exception X::Inheritance::NotComposed when trying to inherit from a stubbed class -- cmp. ticket 81060 (https://rt.perl.org/Ticket/Display.html?id=81060). I don't merge both tickets since that would make things rather confusing IMHO.
On the basis of Moritz's comment and the implemented typed exception, I'm rejecting this ticket. If you don't agree, please reopen.
