Controls direct entry into the Debugger tool.
*enter-debugger-directly* is a generalized boolean which affects the behavior of the LispWorks IDE when an error is signaled outside of the Listener REPL.
nil causes an error notifier window to be displayed (from which you can abort, report a bug, or raise a Debugger tool).
A true value causes the Debugger tool to be displayed immediately, and no error notifier appears.
Errors signaled in a Listener Read-Eval-Print loop are handled in the REPL and therefore
*enter-debugger-directly* has no effect on the behavior in this case.
LispWorks User Guide and Reference Manual - 13 Feb 2015