Currently, it seems error hints have to be defined for a concrete exception type. Indeed, this line

only gets exception handlers for typeof(ex), and not for its supertypes. Would a PR be welcome to change that?

Concrete use case: I have recently added a common error supertype to Enzyme, in order to be able to define hints based on it inside DifferentiationInterface. However, no exception has the type Enzyme.Compiler.EnzymeError, they have concrete subtypes of that which may change between versions since they are internal details.