I know it's nonsensical, but (set! display #f) in a fresh interpreter causes an infinite loop.

Interrupting with Ctrl+C exits guile.

scheme@(guile-user)> (set! display #f)

While reading expression:
Wrong type to apply: Error while printing exception.
While reading expression:
Wrong type to apply: Error while printing exception.
While reading expression:
Wrong type to apply: Error while printing exception.
While reading expression:
Wrong type to apply: Error while printing exception.

[...]

--

bryce