After a little more thought I have a much more minimal failing example:
(while #t
(while #t (break)))
Which gives:
Backtrace:
In ice-9/boot-9.scm:
1784:12 7 (with-exception-handler _ _ #:unwind? _ # _)
In unknown file:
6 (apply-smob/0 #<thunk 73794890e2e0>)
In ice-9/boot-9.scm:
733:2 5 (call-with-prompt _ _ #<procedure default-prompt-handle…>)
In ice-9/eval.scm:
619:8 4 (_ #(#(#<directory (guile-user) 737948911c80>)))
In ice-9/boot-9.scm:
2890:4 3 (save-module-excursion _)
4440:12 2 (_)
In /home/rrt/Software/ursa/bar.scm:
2:14 1 (_)
In unknown file:
0 (_ #<procedure values _>)
