project.clj

(defproject cljs-gwt "0.1.0-SNAPSHOT"
  :description "FIXME: write this!"
  :url "http://example.com/FIXME"

  :dependencies [[org.clojure/clojure "1.5.1"]
                 [org.clojure/clojurescript "0.0-2138"]
                 [compojure "1.0.4"]
                 [hiccup "1.0.0"]]

  :plugins [[lein-cljsbuild "1.0.1"]
            [lein-ring "0.7.0"]]

  :ring {:handler cljs-gwt.core/app}

  :source-paths ["src/clj"]

  :cljsbuild {
               :builds [{:id "dev"
                         :source-paths ["src/cljs"]
                         :compiler {
                                     :output-dir "resources/public/js/out/"
                                     :output-to "resources/public/js/cljs_gwt.js"
                                     :source-map true
                                     :optimizations :none}}
                        {:id "prod"
                         :source-paths ["src/cljs"]
                         :compiler {
                                     :output-to "resources/public/js/cljs_gwt.js"
                                     :optimizations :advanced}}]})

@hsestupin, actually you don't need to set :source-map-path since source maps are produced for every single file.

; The optimization level. May be :whitespace, :simple, or :advanced.
; Defaults to :whitespace.
:optimizations :whitespace

It's from "lein cljsbuild sample". And there is nothing said about :none option. Don't know why, but {:optimization :whitespace} generates working file-structure and sorce maps works well with that

I'm finding the same thing happening to me. :optimizations :whitespace generates the correct file and file structure. But :optimizations :none was giving me this error.