A useful debugging function which causes access to instance to break to the debugger. Accesses include calls to
slot-value and also accessor functions defined by the class of instance. Other instances of the same class are unaffected.
The keyword arguments control which type of access cause a break and are interpreted as described for trace-on-access.
You can remove the break by calling unbreak-on-access.
this function is deprecated. You should now call trace-on-access with
:break t instead.
LispWorks User Guide and Reference Manual - 20 Sep 2017