I copied config/environments/development.rb to config/environments/ci.rb.
When I run with RAILS_ENV=development, the asset search path includes my gem vendor directories, in particular for jquery-ui-rails. However, when I run with RAILS_ENV=ci it does not.
From the console, Rails.application.config.assets.paths evaluates to the following with development
irb(main):002:0> Rails.application.config.assets.paths
=> ["/var/www/ci/conflux/app/assets/images",
"/var/www/ci/conflux/app/assets/javascripts",
"/var/www/ci/conflux/app/assets/stylesheets",
"/var/www/ci/conflux/vendor/assets/stylesheets",
"/opt/comcast/ruby1.9.3/lib/ruby/gems/1.9.1/gems/jquery-rails-1.0.19/vendor/assets/javascripts",
"/opt/comcast/ruby1.9.3/lib/ruby/gems/1.9.1/gems/jquery-ui-rails-1.0.0/vendor/assets/images",
"/opt/comcast/ruby1.9.3/lib/ruby/gems/1.9.1/gems/jquery-ui-rails-1.0.0/vendor/assets/javascripts",
"/opt/comcast/ruby1.9.3/lib/ruby/gems/1.9.1/gems/jquery-ui-rails-1.0.0/vendor/assets/stylesheets"]
but for ci I only get the following:
irb(main):002:0> Rails.application.config.assets.paths
=> ["/var/www/ci/conflux/app/assets/images",
"/var/www/ci/conflux/app/assets/javascripts",
"/var/www/ci/conflux/app/assets/stylesheets",
"/var/www/ci/conflux/vendor/assets/stylesheets",
"/opt/comcast/ruby1.9.3/lib/ruby/gems/1.9.1/gems/jquery-rails-1.0.19/vendor/assets/javascripts"]