+;;; things to consider when tweaking these values:
+;;; * We're afraid to just default them to NIL and NIL, in case the
+;;; user inadvertently causes a hairy data structure to be printed
+;;; when he inadvertently enters the debugger.
+;;; * We don't want to truncate output too much. These days anyone
+;;; can easily run their Lisp in a windowing system or under Emacs,
+;;; so it's not the end of the world even if the worst case is a
+;;; few thousand lines of output.
+;;; * As condition :REPORT methods are converted to use the pretty
+;;; printer, they acquire *PRINT-LEVEL* constraints, so e.g. under
+;;; sbcl-0.7.1.28's old value of *DEBUG-PRINT-LEVEL*=3, an
+;;; ARG-COUNT-ERROR printed as
+;;; error while parsing arguments to DESTRUCTURING-BIND:
+;;; invalid number of elements in
+;;; #
+;;; to satisfy lambda list
+;;; #:
+;;; exactly 2 expected, but 5 found
+(defvar *debug-print-level* 5