Compilation error due to inheriting from an ineligible type
does X::Comp
Compile time error thrown when trying to inherit from a type that does not support inheritance (like a package or an enum).
For example
<Ax Ay>;is A ;
dies with
===SORRY!===A does not support inheritance, so B cannot inherit from it
The name of the type that tries to inherit.
The type object that the child tried to inherit from.