alt with an empty cat breaks explain

Question

(s/conform (s/alt :empty (s/cat)) [42]) ; => ::s/invalid (s/explain (s/alt :empty (s/cat)) [42]) ; => prints 'Success!'

Related:
CLJ-2360 - looks like the same issue, but for s/and, s/or
CLJ-2336 - looks like a consequence of this issue
CLJ-2304 - probably related too

Answer 1

Reference: https://clojure.atlassian.net/browse/CLJ-2371 (reported by jcr)