How is the :assets group in rails 3.1 handled by bundler?

Question

I don\'t understand what exactly is going on with this group, and what bundler is doing with it. Is it only loaded in dev mode? What if I want to make a new environment type

Answer 1

To elaborate a little on the answer, from rails asset pipeline guide:

a) by default they are NOT included in production:

# Gems used only for assets and not required
# in production environments by default.

b) If you add a new environment type, you would want to handle it according to Dmitry's answer above. That is, add it as one of the groups that will require it.