thin version mismatch with gemfile trying to install discourse

Question

i am trying to install thin version 1.5.0 but as default when i install with gem install thin it install 1.5.1 then i get this error

>> Writing PID to tmp/pids/thin.0.pid
>> Using rack adapter
>> Exiting!
/var/lib/gems/1.9.1/gems/bundler-1.3.5/lib/bundler/runtime.rb:33:in `block in setup': You have already activated thin 1.5.1, but your Gemfile requires thin 1.5.0. Using bundle exec may solve this. (Gem::LoadError)
        from /var/lib/gems/1.9.1/gems/bundler-1.3.5/lib/bundler/runtime.rb:19:in `setup'

Answer 1

I ran

gem uninstall thin

Which listed the versions of thins that are installed. I uninstalled 1.5.1 to fix the issue.

Answer 2

maybe overkill, but try to delete your Gemfile.lock, change the version of your thin in Gemfile and run bundle install