Thin version mismatch with gemfile trying to install discourse

General
1

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'
2

The error you’re seeing indicates a mismatch between the version of the thin gem that’s installed and the version specified in your project’s Gemfile. Here’s how you can fix it by installing and using version 1.5.0 specifically:

Step-by-step Fix:

1. Uninstall the current version of thin (optional):

If you’re not using version 1.5.1 elsewhere, you can uninstall it:

gem uninstall thin -v 1.5.1

2. Install version 1.5.0 explicitly:

gem install thin -v 1.5.0

3. Make sure your Gemfile specifies the correct version:

Edit your Gemfile to include:

gem 'thin', '1.5.0'

4. Install gems via Bundler to respect the Gemfile:

bundle install

5. Run your app using bundle exec to avoid version conflicts:

bundle exec thin start

Why This Happens:

RubyGems will install the latest version of a gem unless you specify a version. But if your project’s Gemfile requires a different version, you’ll get the Gem::LoadError. Running commands with bundle exec ensures that the versions in your Gemfile.lock are used, preventing these mismatches.