Using Bundler.:
Click here if you are interested to see the solution.
Changing rubygems version:
- Downgrade the rubygems to an earlier version using
gem update --system {version} - Add "
require 'thread'" in to - Rakefile, script/server and config/environment.rb
Upgrade Rails:
Upgrade application in to Rails 3 though it's very hard to do for existing/running rails application.
For me, I was trying to run Rails 2.3.5 application where my system had rubygems 1.8.2. I've changed the rubygems version in to 1.7.2 as mentioned above and everything works fine.