Redefining most clojure.core fns e.g. defn or defmacro doesn't work

[cldwalker]

From LightTable/LightTable#1828:

This (defmacro defn [name & body] (clojure.core/defn ~name ~@Body))works fine in the Clojure repl, but results inclojure.lang.Compiler$CompilerException: java.lang.RuntimeException: Can't create defs outside of current ns, compiling:(null:6:1)` in LightTable Instarepl.