reply to the UPDATE:

Ike, I didn't complain about your code I just explained why I decided to patch diagnostics.

> I said "something like" the code that follows. I figured you were smart enough to get it to work. Note that it doesn't mark other lines as "info", it doesn't properly tag multi-line warnings and errors, and it doesn't handle programs that don't return a true value.

I know you said "something like" and I appreciate your help. But after reading the docs for %SIG in perlvar multiple(!) times without getting it to work I decided that patching diagnostics might be even "smarter".