Chain-Debugger-Hook names a function, with lambda list NIL:
Create a function that calls TOOTSVILLE DEBUGGER-HOOK.
The present value of *DEBUGGER-HOOK* (see the Common Lisp HyperSpec) is closed over by that function, and will be called after calling TOOTSVILLE DEBUGGER-HOOK.
Defined in file src/lib/rollbar/rollbar.lisp.