我正在尝试运行本教程中的代码：http://railscasts.com/episodes/316-private-pub
我从github下载了源代码并按照说明进行操作，然后运行
rackup private_pub.ru -s thin -E production瘦服务器无法启动。
>> Thin web server (v1.3.1 codename Triple Espresso)
>> Maximum connections set to 1024
>> Listening on 0.0.0.0:9292, CTRL+C to stop
/home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/eventmachine-0.12.10/lib/eventmachine.rb:572:in `start_tcp_server': no acceptor (RuntimeError)
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/eventmachine-0.12.10/lib/eventmachine.rb:572:in `start_server'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/thin-1.3.1/lib/thin/backends/tcp_server.rb:16:in `connect'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/thin-1.3.1/lib/thin/backends/base.rb:53:in `block in start'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `call'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run_machine'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/thin-1.3.1/lib/thin/backends/base.rb:61:in `start'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/thin-1.3.1/lib/thin/server.rb:159:in `start'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/rack-1.3.6/lib/rack/handler/thin.rb:13:in `run'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/rack-1.3.6/lib/rack/server.rb:265:in `start'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/rack-1.3.6/lib/rack/server.rb:137:in `start'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/gems/rack-1.3.6/bin/rackup:4:in `<top (required)>'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/bin/rackup:19:in `load'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/bin/rackup:19:in `<main>'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/bin/ruby_noexec_wrapper:14:in `eval'
from /home/jatin/.rvm/gems/ruby-1.9.2-p320/bin/ruby_noexec_wrapper:14:in `<main>'
如何摆脱此错误？