<entry-trap> class implements traps that are triggered upon
any stack frame entry. No further parameters are needed to specify an
instance of this class, so there are no class-specific trap options.
Note that it remains possible to use the common trap options
(see Common Trap Options), for example to set a trap for the
nth next frame entry.
(install-trap (make <entry-trap> #:skip-count 5 #:behaviour gds-debug-trap))