suite_condition("Yajl not supported for JRuby") do
  RUBY_PLATFORM != 'java'
end

gemfile <<-RB
  gem 'rack'
  gem 'yajl-ruby', '~> 1.2.1'
RB

gemfile <<-RB
  gem 'rack'
  gem 'yajl-ruby', '~> 1.1.0'
RB