Take the tour ×  In Rails 3, gems used exclusively to generate
assets in the asset pipeline were properly placed in the assets
group of the Gemfile:   # Gems used only for assets and not
required # in production environments by default. group :assets
do   gem 'sass-rails'   gem 'coffee-rails'   gem 'uglifier'    #
gem 'therubyracer', :platforms => :ruby  Now, according to the
(still in progress) upgrade documentation:   Sure enough, making
a new project with RC1 yields a Gemfile with asset-related gems
included by default outside of any group:  source
'https://rubygems.org'  gem 'rails', '4.0.0.rc1'  # Use sqlite3
as the database for Active Record gem 'sqlite3'  # Use SCSS for
stylesheets gem 'sass-rails', '~> 4.0.0.rc1'  # Use Uglifier as
compressor for JavaScript assets gem 'uglifier', '>= 1.3.0'  #
Use CoffeeScript for .js.coffee assets and views gem 'coffee-
rails', '~> 4.0.0'  # gem 'therubyracer', platforms: :ruby
Does this mean these gems will now be bundled in production
builds by default? If so, why