MKCL fails when non-erroneous condition is signaled

[Faré]

Dear Jean-Claude,

ASDF 3.3 (the "plan" branch) is failing miserably on MKCL, because it
signals a non-serious condition (that is only handled in some
contexts) as a way to detect out-of-date .asd files. All other CL
implementations know to ignore such conditions when they are not
handled. But instead MKCL borks with error messages such as:

Unhandled condition signaled during command line arguments processing:
system test-asdf is out of date.

I believe it's a bug in MKCL, maybe specifically in command line processing.
Can you fix it?

Should I add some backward compatibility for older versions of MKCL,
or is it superfluous?

—♯ƒ • François-René ÐVB Rideau •Reflection&Cybernethics• http://fare.tunes.org
"Wherever you go, there you are!" Dual: "Wherever you are, thence you go."
Beats "I'll start exercising as soon as I'm into shape."