     debug 'child exited', code, signal
     return if returned
     returned = true
-    return callback new Error "Child '#{cmd}' (pid=#{child.pid}) exited with #{code} #{signal}"
+    return callback new Error "Child '#{execCmd}' (pid=#{child.pid}) exited with #{code} #{signal}"
   return child
 
 participantCommands = (graph, library, only, ignore) ->

      return cb err if err
      return cb err, { name: name, command: cmd, child: child }

  debug 'starting participants', commands
  names = Object.keys commands
  async.map names, start, (err, processes) ->
    return callback err if err

  else
    prog = cmd.split(' ')[0]
    args = cmd.split(' ').splice(1)
  execCmd = prog + ' ' + args.join(' ')

  childoptions =
    env: env
  debug 'participant process start', execCmd
  child = child_process.spawn prog, args, childoptions
  returned = false
  child.on 'error', (err) ->
