line 35 is a problem I'm having in Quil, the Clojure interface to Processing.

quil-wtf.clj

(ns circles.core
  (:require [quil.core :as q]))

; "hello world" for Quil meets http://bit.ly/18luJO2

(def the-width 808)
(def the-height 500)

(defn random-x-y []
  (list (int (rand the-width))
        (int (rand the-height))))

(defn circle [xy]
  (q/stroke 171 163 225)
  (q/stroke-weight 5)
  (q/fill 213 209 240)

  (let [diam (+ 50 (q/random 100))
        x (first xy)
        y (second xy)]
    (q/ellipse x y diam diam)))

(defn log-xy [a-list]
  (println (str "x: " (first a-list) " "
                "y: " (second a-list))))

(defn setup []
  (q/smooth)
  (q/frame-rate 20)
  (q/background 0)
  (let [xy (random-x-y)]
    ; this totally works
    (circle (random-x-y)))
    ; this totally fails
    (map circle (list (random-x-y) (random-x-y)))
)

(defn draw [] ())

(q/defsketch example
  :title "Circles"
  :setup setup
  :draw draw
  :size [the-width the-height])

(defn -main [] ())

Whenever you have a problem with Clojure, pretty much first thing to investigate is laziness :-)

In this case you can wrap the call to map with dorun :-)