error log

$ bundle exec rake
Run options: 
# Running tests:
..../home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:526:in `start_tcp_server': no acceptor (port is in use or requires root privileges) (RuntimeError)
  from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:526:in `start_server'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/em-proxy-0.1.8/lib/em-proxy/proxy.rb:10:in `block in start'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:187:in `call'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:187:in `run_machine'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:187:in `run'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/em-proxy-0.1.8/lib/em-proxy/proxy.rb:5:in `start'
	from /home/travis/build/v-yarotsky/turnout_proxy/lib/turnout_proxy.rb:7:in `run'
	from /home/travis/build/v-yarotsky/turnout_proxy/bin/turnout_proxy:42:in `<main>'
./home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:526:in `start_tcp_server': no acceptor (port is in use or requires root privileges) (RuntimeError)
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:526:in `start_server'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/em-proxy-0.1.8/lib/em-proxy/proxy.rb:10:in `block in start'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:187:in `call'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:187:in `run_machine'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/eventmachine-1.0.3/lib/eventmachine.rb:187:in `run'
	from /home/travis/.rvm/gems/ruby-1.9.3-p327/gems/em-proxy-0.1.8/lib/em-proxy/proxy.rb:5:in `start'
	from /home/travis/build/v-yarotsky/turnout_proxy/lib/turnout_proxy.rb:7:in `run'
	from /home/travis/build/v-yarotsky/turnout_proxy/bin/turnout_proxy:42:in `<main>'
E
Finished tests in 2.774274s, 2.1627 tests/s, 1.8023 assertions/s.

hello_server.rb

require 'rubygems'
require 'bundler/setup'
require 'support/travis_spawn'
require 'eventmachine'

class HelloServer
  include TravisSpawn

  def initialize(port, message)
    @pid = spawn("ruby -Itest #{__FILE__} #{port} #{message}")
    at_exit { die }
  end

  def pid
    @pid
  end

  def die
    Process.kill(:SIGQUIT, pid)
  end
end

def HelloServer(response)
  Module.new do
   define_method :receive_data do |data|
     send_data "HTTP/1.1 200 OK\r\nContent-Length: #{response.length}\r\n\r\n#{response}"
     close_connection_after_writing
   end
  end
end

if $0 == __FILE__
  EventMachine.run do
    EventMachine.start_server "0.0.0.0", ARGV[0].to_i, HelloServer(ARGV[1] || "OK")
  end
end

travis_spawn.rb

require 'posix/spawn'

module TravisSpawn
  include POSIX::Spawn

  def spawn(command, *args)
    if ENV["TRAVIS"]
      command = "rvmsudo " + command
    end
    super(command, *args)
  end
end