Re: Why does this thread code crash my emacs?

[dick]

While the case in question is pedagogical (and as such, any workaround
comes to nothing), I cannot but indulge my urge to de-obfuscate
(cl-letf is a friend and patriot):

emacs-26.3 -Q -l cl --eval                                        \
"(lexical-let* ((thread2                                          \
                 (make-thread                                     \
                  (lambda ()                                      \
                    (cl-letf (((symbol-function (quote sit-for))  \
                               (lambda (secs &optional nodisp)    \
                                 (sleep-for secs)                 \
                                 (or nodisp (redisplay))          \
                                 t)))                             \
                      (hanoi 11)))))                              \
                (thread1                                          \
                 (make-thread                                     \
                  (lambda ()                                      \
                    (sleep-for 10)                                \
                    (thread-signal thread2 (quote error) nil))))))"