ruby on rails 3 - Thin web server: `start_tcp_server': no acceptor (RuntimeError) after git branch checkout

Question

A Rails 3.2.0 app, working fine with Thin web server, both locally and on Heroku cedar stack.

After:

$ git branch work
$ git checkout work
$ rails server

I get:

=> Booting Thin
=> Rails 3.2.0 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
>> Thin web server (v1.3.1 codename Triple Espresso)
>> Maximum connections set to 1024
>> Listening on 0.0.0.0:3000, CTRL+C to stop
Exiting
/Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/eventmachine-0.12.10/lib/eventmachine.rb:572:in `start_tcp_server': no acceptor (RuntimeError)
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/eventmachine-0.12.10/lib/eventmachine.rb:572:in `start_server'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/thin-1.3.1/lib/thin/backends/tcp_server.rb:16:in `connect'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/thin-1.3.1/lib/thin/backends/base.rb:53:in `block in start'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `call'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run_machine'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/eventmachine-0.12.10/lib/eventmachine.rb:256:in `run'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/thin-1.3.1/lib/thin/backends/base.rb:61:in `start'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/thin-1.3.1/lib/thin/server.rb:159:in `start'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/rack-1.4.1/lib/rack/handler/thin.rb:13:in `run'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/rack-1.4.1/lib/rack/server.rb:265:in `start'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.0/lib/rails/commands/server.rb:70:in `start'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.0/lib/rails/commands.rb:55:in `block in <top (required)>'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.0/lib/rails/commands.rb:50:in `tap'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/gems/railties-3.2.0/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

Also, when I do:

sudo bundle exec rails server thin -p 3000

I get:

/Users/peter/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/dependency.rb:247:in `to_specs': Could not find bundler (>= 0) amongst [bigdecimal-1.1.0, io-console-0.3, json-1.5.4, minitest-2.5.1, rake-0.9.2.2, rdoc-3.9.4] (Gem::LoadError)
from /Users/peter/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems/dependency.rb:256:in `to_spec'
from /Users/peter/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/site_ruby/1.9.1/rubygems.rb:1210:in `gem'
from /Users/peter/.rvm/gems/ruby-1.9.3-p125/bin/bundle:18:in `<main>'

I have bundler 1.0.22 installed. Updated and installed it. Nothing seems to work. Any ideas?

Answer 1

This works for me. Find (zombie?) server (can happen when quitting terminal with server running):

$ ps ax | grep rails

If it returns something like:

33467 s002 S+ 0:00.00 grep rails
33240 s003 S+ 0:15.05 /Users/Arta/.rbenv/versions/1.9.2-p290/bin/ruby script/rails s -p 3000

kill it, and run anew:

$ kill -9 33240
$ rails s