Kevin McKelvin

Rails 3.2 Released - The upgrade story

23 January 2012

Rails 3.2 was released on Friday 20 January. So as any good Rails developer would, I started playing around with it on an app I’m building.

It was a breeze getting the bundle updated, just add these lines to the Gemfile and run bundle update

gem 'rails', '3.2.0'
gem 'sass-rails',   '3.2.3'
gem 'coffee-rails', '~> 3.2.1'
gem 'uglifier', '>= 1.0.3'

Once the updated gems had installed, firing up the rails server spat a few errors out. It turns out ActiveAdmin v0.3.4 doesn’t work with Rails 3.2. Within a few hours of the Rails release there was already a fix for this which has been pulled into the activeadmin Github repo.

Bundling against the edge release is risky, but it works and all my tests were still passing:

gem 'activeadmin', git: 'git://'

The last issue I had was related to using Ruby 1.9.3. WEBrick has a few issues, so I switched over to using Thin in development instead.

gem 'thin'

Overall I’ve noticed a significant improvement in speed in Rails 3.2’s development environment using Ruby 1.9.2. It feels even faster when I ramp it up to Ruby 1.9.3.

Check out the Rails 3.2 release announcement and the upgrade instructions doc.

Kevin McKelvin

These are the online musings of Kevin McKelvin. He is the CTO at Resource Guru, and lives in Newcastle upon Tyne, UK.