Reports type arguments used in an inheritance statement (a superclass clause, self-type, or an inclusion call) which have incorrect variances. Type arguments passed to an inheritance statement must match in variance with the declaring type variable.

Example:

module Enumerable[unchecked out A]
end

class Example[in A]
  # Contravariant type variable 'A' of class 'Example' used as a covariant argument
  include Enumerable[A]
end