(or (delivery-value :keep-debug-mode)
(< *delivery-level* 5))
If the value is
nil, the functions and values used to read Lisp expressions are deleted. This means that the listener no longer works. On non-Windows platforms it also prevents
capi:top-level-interface-geometry-key from working.
:keep-lisp-reader keyword is set to
t automatically if :keep-debug-mode is
LispWorks Delivery User Guide - 10 Aug 2017