   else
     prog = cmd.split(' ')[0]
     args = cmd.split(' ').splice(1)
-  cmd = prog + ' ' + args.join(' ')
+  execCmd = prog + ' ' + args.join(' ')
 
   childoptions =
     env: env
-  debug 'participant process start', cmd
+  debug 'participant process start', execCmd
   child = child_process.spawn prog, args, childoptions
   returned = false
   child.on 'error', (err) ->

      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

    debug 'child exited', code, signal
    return if returned
    returned = true
    return callback new Error "Child '#{execCmd}' (pid=#{child.pid}) exited with #{code} #{signal}"
  return child

participantCommands = (graph, library, only, ignore) ->
