title: How to change Ruby Version for rails application
body: <p>Having some serious issues with Ruby at the moment and I have a feeling it's around versioning. </p>
  
  <p>I have a Gemfile that looks like this</p>
  
  <pre><code>source "https://rubygems.org"
  
  ruby "2.5.2"
  
  gem "rails", "4.2.1"
  gem "unicorn", "4.8.3"
  gem "mysql2"
  gem "sass-rails", "~&gt; 4.0.3"
  gem "uglifier", "&gt;= 1.3.0"
  gem "coffee-rails", "~&gt; 4.0.0"
  gem "turbolinks"
  gem "ancestry"
  gem "kaminari"
  gem "saxerator"
  gem "factory_girl_rails"
  gem "delayed_job_active_record"
  gem "tree_delta", "~&gt; 2.0.0"
  gem "daemons"
  gem "which-user",      git: "https://ad131a5ab23a69365434b0e7e36d6275b6a1e9fb:x-oauth-basic@github.com/whichdigital/which-user.git", ref: '18eb7'
  gem "eva_rails",       git: "https://ad131a5ab23a69365434b0e7e36d6275b6a1e9fb:x-oauth-basic@github.com/whichdigital/eva_rails.git", tag: "v1.0.6"
  gem "dam_client",      git: "https://ad131a5ab23a69365434b0e7e36d6275b6a1e9fb:x-oauth-basic@github.com/whichdigital/digital_asset_manager_client.git", tag: "1.0.0"
  gem "fragment_client", git: "https://ad131a5ab23a69365434b0e7e36d6275b6a1e9fb:x-oauth-basic@github.com/whichdigital/fragment_client.git", ref: '3c197'
  gem 'frontend_containers', git: "https://ad131a5ab23a69365434b0e7e36d6275b6a1e9fb:x-oauth-basic@github.com/whichdigital/frontend_containers.git"
  gem "cucumber-rails", require: false
  gem "parallel_tests"
  gem "elasticsearch"
  gem 'patron'
  gem 'typhoeus'
  gem 'net-http-persistent'
  gem "dalli"
  gem "jbuilder"
  gem "newrelic_rpm"
  gem 'airbrake'
  gem 'rest-client'
  gem 'redis-rails'
  gem 'dotenv-rails', :require =&gt; 'dotenv/rails-now'
  gem 'mail'
  gem 'rack-rewrite', '~&gt; 1.5.0'
  gem 'net-sftp'
  gem 'httparty'
  
  group :production do
    gem 'rails_12factor'
  end
  
  group :test do
    gem "timecop"
    gem "webmock"
    gem "site_prism"
    gem "simplecov", require: false
  end
  
  group :development, :test do
    gem "rspec-rails"
    gem "rspec-its"
    gem "shoulda-matchers", require: false
    gem "database_cleaner"
    gem "spring"
    gem "spring-commands-rspec"
    gem "spring-commands-cucumber"
    gem "pry-rails"
    gem "pry-byebug"
    gem "rubocop", require: false
    gem "selenium-webdriver"
    gem "poltergeist"
    gem "capybara-firebug"
    gem "capybara-screenshot"
    gem "yarjuf"
    gem "launchy"
    gem "web-console", "~&gt; 2.0"
    gem "bullet"
    gem "rspec-collection_matchers"
    gem "eyes_selenium"
    gem 'ftpd'
  end
  </code></pre>
  
  <p>I have <code>Bundler version 1.11.2</code> installed.</p>
  
  <p>Gem version <code>2.4.6</code> </p>
  
  <p>Rails <code>4.2.5.1</code></p>
  
  <p>When I execute <code>ruby -v</code> I get this returned <code>ruby 2.0.0p645 (2015-04-13 revision 50299) [universal.x86_64-darwin15]</code></p>
  
  <p>The read me file that came with this project said to run <code>"bin/setup"</code> which then prompted me to install <code>bundler</code>. Installed as you see above. </p>
  
  <p>As that command is running I get the following error <code>Your Ruby version is 2.0.0, but your Gemfile specified 2.5.2</code></p>
  
  <p>I cannot for some reason update to this version. </p>
  
  <p>If anyone needs anymore information please let me know.</p>