   minify:     false
   output:     []
   prelude:    null
+  sourceMap:  true
   strict:     false
   stripDebug: false
   watch:      false

    -o, --output <file>          write bundle to file instead of stdout, {} may be used as a placeholder
    -p, --prelude <file>         file to use as prelude
        --no-prelude             exclude prelude from bundle
        --prelude-only           only output prelude
    -s, --strict                 add "use strict" to each bundled module
        --strip-debug            strip `alert`, `console`, `debugger` statements

      opts.prelude = args.shift()
    when '--no-prelude'
      opts.prelude = false
    when '--no-source-map'
      opts.sourceMap = false
    when '--prelude-only'
      opts.preludeOnly = true
    when '-s', '--strict'
