I think the name can be improved. If I see an X::File::NotFound exception, I'd expect it to be used for something like open "i/dont/exist" or similar situations. In those, the repository list in the error message doesn't make sense. Maybe X::File::NotFoundInRepository or X::File::NotFound::InRepository or something like that. Is this even about files? We're trying to load mouldes, aren't we?