Clojure bug report: https://groups.google.com/forum/?fromgroups=#!topic/light-table-discussion/W1FBd9Ydgfc

broken.clj

; Gives warning: Assert failed....
(ns light.core
(:use [clojure.pprint]))
(def p pprint)
  
(+ 1 1)

(def x (into {} (map (fn [x] [x (inc x)]) (take 1000 (range)))))
 
(pprint x)
 
(pprint 8)

working.clj

(ns light.core
   (:use [clojure.pprint :only [pprint]]))
(def p (comp println pprint))
 
(+ 1 1)

(def x (into {} (map (fn [x] [x (inc x)]) (take 1000 (range)))))
 
(p x)
 
(p 8)