gistfile1.clj

(def a {:x 1})
(def b {:x/y 2})

(prn a) ;; => 1                                                                                                                                                                                                     
(prn b) ;; => 2                                                                                                                                                                                                     

(let [{:keys [x]} a]
  (prn x)) ;; => 1                                                                                                                                                                                                  

(let [{:keys [x/y]} a]
  (prn x/y)) ;; => java.lang.RuntimeException: Can't let qualified name: x/y