Suppressing error message "-- an error. To debug this try: debugmode(true); "

I often use the error() function for displaying specific error messages in
my Maxima programs.
I'd like to display only my message and not the " -- an error. To debug
this try: debugmode(true);" too. This is both for an aesthetic reason and
because there is no need for the user to start a debugging session, since
errors displayed to the user are caught at a high level. For example:

(%i1) error("This is an error");

This is an error
 -- an error. To debug this try: debugmode(true);

I'd like to have only

(%i44) error("This is an error");

This is an error


Unfortunately, setting errormsg to false suppresses only my message, and
I've found no way to delete the message related to debugmode.

Thanks
Stefano