You can control the behavior and appearance of the debugger using the Preferences dialog.
To do this, raise the Preferences dialog by one of the methods described in Setting preferences and select Debugger in the list on the left side of the dialog.
Figure 11.4 Debugger Preferences
By default, the call frame for each active function call in the backtrace is listed in the Backtrace area. There are a number of other types of call frame which are hidden by default. Display call frames of these types by selecting them in the View Frame panel of the debugger Preferences:
Displays all the binding frames in the Backtrace list.
Lists the catch frames in the Backtrace list.
Lists the handler frames in the Backtrace list.
Lists any hidden symbols in the Backtrace list.
Lists all the restart frames in the Backtrace list. Each restart frame is listed, with the restart action to be taken given in brackets. To restart execution at any restart frame, select the frame, and choose Debug > Frame > Restart Frame .
Lists all invisible frames (such as the call to the error function itself) in the Backtrace list.
Note that all these commands can be toggled: choosing any command switches the display option on or off, depending on its current state. By default, all the options are off when the debugger is first invoked.
As with other tools, you can configure the way package names are displayed in the debugger tool in the Package box of the Debugger Preferences.
Check Show Package Names to turn the display of package names in the Backtrace and Variables lists on and off.
Specify a package name in the text box to change the process package of the debugger tool. You can use
completion
to reduce typing: click on 
to which allows you to select from a list of all package names which begin with the partial input you have entered. See Completion for detailed instructions.
By default, the current package is the same as the package from which the error was generated.
By default, when you close the Debugger window it attempts to abort, that is to call the abort restart.
Uncheck the Abort When Closed option only if you want to turn off this behavior.
To choose to view frames and variables in two lists rather than one tree, select the value Two list-panels in the Frames and Variables option.
The Remote tab is described in Configuring Remote Debugging.
LispWorks IDE User Guide (Macintosh version) - 13 Sep 2017