> Marco Antoniotti wrote:
>
> > Now, this is a specific case for me: having a consistent
> > READER-ERROR-BECAUSE-THERE-IS-NO-SUCH-PACKAGE-THAT-THE-SYSTEM-KNOWS
> > error signaled would simplify some code writing.

I agree with the sentiment, what is the specific proposal may need more work. Would you want this same condition to be signaled for this form?

(defpackage :foo
  (:use :not-yet-loaded))

That's an error, but not a reader error the way reading not-yet-loaded:bar would be. Still, it would be nice if these shared a common superclass because what the application might want to do to handle would be the same. Unfortunately, the condition system does not portably support multiple inheritance.