How to use nanoc with rerun

config.ru

require 'bundler'
Bundler.require(:default, :server)

use Rack::Static,
  :urls => ["/"],
  :root => "output",
  :index => 'index.html'

run Rack::File.new('output/')

Rakefile

task :server do
  fork do
    exec 'bundle exec rackup -p 4567'
  end
  exec %{rerun -p "{Rules,Gemfile,content/**/*,lib/**/*,static/**/*,layouts/**/*}" -x nanoc compile}
end