When expanding:
(quiet! ...)
You'd expect (simplified for explanation):
(letf! ((standard-output ...)
((symbol-function #'message) ...)
((symbol-function #'load-file) ...)
((symbol-function #'write-region) ...))
...)
But instead get:
(letf! ((standard-output ...))
;; where'd the other binds go?
...)
This was due to data-loss caused by nreverse's destructive mutation of
the given bindings.
Also: silences byte-compiler complaining about unused bindings.
68709fe93a