Cannot start workling_starling_client in rails production environment

export RAILS_ENV=production

RAILS_ENV=production god -d config/monitor_daemons.god -t

STARLING_PORT = ENV['RAILS_ENV'] == 'production' ? '-p 15151' : ''

God.watch do |w|
  ...
  w.start = "starling -d -P log/starling.pid -q log/ #{STARLING_PORT}"
  ...
end

God.watch do |w|
  ...
  w.start = "script/workling_starling_client start"
  ...