Request for assistance: (assertion-violation) unbound variable

[Peter Silcock]

As a newcomer to Guile/Scheme, I am working my way through some
exercises which require the use of an (assertion-violation) procedure
to trap an error condition, specifically:

(if (empty? queue)
    (assertion-violation 'getq "Queue is empty")))

When I run the code (which I have checked with the answer given in the
book), I am presented with the following output: "In procedure module-
lookup: Unbound variable: assertion-violation."

So far I have found no pointers to a solution in the reference manual
or on the web.  My assumption is that I am missing a module or library
from somewhere, but don't know how to set about identifying it. Chicken
Scheme also responds with the same error.

Guile version 2.0.13 on Debian Stretch 4.9.0-3-amd64.

Any suggestions please? Thanks in anticipation,

Peter Silcock