Develop with Rails 3 when Rails 4 is already installed

Question

I have to begin local development of this open-source project, but it uses Rails 3.2.21, and I already have Rails 4.x installed. How can I specify that I want to work with Rails 3 only when working on this app?

Answer 1

You should use a ruby version manager, something like rvm, rbenv or chruby, each doc will tell you what to do.

This way you could have different ruby versions installed, and with bundler you could use different rails versions according to the Gemfile.

Just add a .ruby-version file inside the project root, and the version manager should detect it.

Answer 2

If you will change the rails version directly in Gemfile, it may raise issue for compatibility later:

Instead use RVM or other related version manager and after isntalling use below command: - rvm use 1.9.3 - bundle install - Then mention the version in Gem file

Answer 3

To use the specific rails version with your app you can do this:

rails _3.2.21_ myApp

If you don't already have rails 3.2.21 installed just run this:

gem install 'rails' -v '3.2.21'

Answer 4

In your Gemfile specify the rails version you want that project to use:

# Gemfile

gem "rails", "~> 3.2.21"