Rails 3.2 was released on Friday 20 January. So as any good 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

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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:

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gem 'activeadmin', git: 'git://github.com/gregbell/active_admin.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.

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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.