cannot load such file -- thin (LoadError) while running rackup private_pub.ru -s thin -E production command

Question

I am referring to the pub railscast tutorial and have followed all steps properly but while running last command i.e.

rackup private_pub.ru -s thin -E production

to rackup the faye server I am getting following error:

/usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': cannot load such file -- thin (LoadError)
from /usr/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/handler/thin.rb:1:in `<top (required)>'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/handler.rb:20:in `const_get'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/handler.rb:20:in `block in get'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/handler.rb:20:in `each'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/handler.rb:20:in `inject'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/handler.rb:20:in `get'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:268:in `server'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:264:in `start'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/lib/rack/server.rb:141:in `start'
from /var/lib/gems/1.9.1/gems/rack-1.5.2/bin/rackup:4:in `<top (required)>'
from /usr/local/bin/rackup:19:in `load'

Answer 1

Have you already installed thin?

You can install a gem using the gem command: gem install thin

Or alternatively use Bundler, add thin to the Gemfile then run bundle install (of course you will need the bundler gem for this)