unexpected interaction between set_interrupt_handler and set_event_handler

Normally, instantiation error is raised for the following:

[eclipse 8]: set_interrupt_handler(X,Y).
instantiation fault in set_interrupt_handler(X, Y)

However, if a handler is defined for event 3 (an error that is not
defined):

[eclipse 9]: set_event_handler(3,undef/1).

yes.
[eclipse 10]: set_interrupt_handler(X,Y).
accessing an undefined procedure from set_interrupt_handler(X, Y) in module eclipse
[eclipse 11]:

if undef/1 is defined, then the instantiation error is again raised, and
undef/1 is apparently not called:

[eclipse 11]: [user].
 undef(X) :- write(hello-X).
 user       compiled traceable 92 bytes in 0.00 seconds

yes.
[eclipse 12]: set_interrupt_handler(X,Y).
instantiation fault in set_interrupt_handler(X, Y)