Clojail does not throw Security Exception in Clojure

Question

I'm using clojail library for sandboxing but it does not behave as expected.

Here is the code:

(ns jail.core
  (:require [clojail.core :as s]
            [clojail.testers :as t]))

(def my-tester [(t/blacklist-objects [clojure.lang.RT])
                (t/blanket "clojail")])

(def sb (s/sandbox my-tester))

(println (sb '(do
                (import clojure.lang.RT)
                (RT/errPrintWriter))))

At (import clojure.lang.RT) line it has to throw SecurityException but it does not.

It returns PrintWriter(errPrintWriter) object.

Answer 1

It turns out if I don't pass the class object to import macro, it just works but I think the behaviour is kinda odd.

Here:

(println (sb '(do
                clojure.lang.RT
                (RT/errPrintWriter))))

Now I'm getting Security Exception, the import macro somehow prevents clojail to throw Security Exception .