set-default-remote-debugging-connection sets connection as the default connection for the remote debugging interface on the client side (used when entering the debugger and by calls to start-remote-listener and remote-inspect).
The default connection is used when the enabling switch is
t, which it typically is because that is the default in start-client-remote-debugging-server and configure-remote-debugging-spec. The switch can also be set by set-remote-debugging-connection and in a dynamic scope by with-remote-debugging-connection and with-remote-debugging-spec.
See set-remote-debugging-connection for a discussion about the enabling switch.
LispWorks User Guide and Reference Manual - 20 Sep 2017