(or (< severity 5) (delivery-value :keep-debug-mode)) If this is nil , functions for handling the top level read-eval-print loop are deleted. Note that this means that if the line based debugger is invoked, there is no way to communicate with it
If this is non- nil , the top level history is also cleared when the severity level is higher than 0 .
Affected by: :keep-debug-mode