With the enhanced error printing, you can see that the source is often indicated using a <cljs repl> indicator.
With the same feature in Clojure the source is {{REPL}}.
Compare:
ClojureScript:
cljs.user=> (ffirst 1)
Execution error (Error) at (<cljs repl>:1).
1 is not ISeqable
Clojure:
user=> (ffirst 1)
Execution error (IllegalArgumentException) at user/eval1 (REPL:1).
Don't know how to create ISeq from: java.lang.Long
This enhancement asks that source simply be referred to as {{REPL}} as is done in Clojure.
