What is a Rack - "no acceptor" error?

rack, ruby, thin

Solution

As @Fivell says, I think the problem is that you have a previous instance of `thin` still running. Rather than start on another port though, I would recommend killing the previous instance. Something like this should do the job (I recreated the problem here, so this is real output on my end):

telemachus caps $ ps ax | grep ruby
  153   ??  S      7:52.18 ruby /usr/local/bin/djsd
15801   ??  S      0:00.40 ruby caps.rb  # this is our problem, get it's PID
15973 s000  S+     0:00.00 grep ruby

telemachus caps $ kill -9 15801 # thin needs -9 - hard to kill
telemachus caps $ ps ax | grep ruby
  153   ??  R      7:52.86 ruby /usr/local/bin/djsd
16057 s000  S+     0:00.00 grep ruby

Depending on how you started your app, you may need to `grep` for something different (say if you used `shotgun` or `rackup`).

Problem

While trying to run my config.ru, I'm getting an odd error I can't seem to debug called a 'No acceptor' error. Full error message: ``` eventmachine.rb:572:in `start_tcp_server': no acceptor (RuntimeError) ``` Does anyone know what this error means? Thanks.

Original source