Ye,s but if your CI isn't terrible, you have the dependencies cached, so that subsequent runs are almost instant, and more importantly, you don't have a hard dependency on a third party service.
The reason for speeding up bundler isn't CI, it's newcomer experience. `bundle install` is the overwhelming majority of the duration of `rails new`.
The reason for speeding up bundler isn't CI, it's newcomer experience. `bundle install` is the overwhelming majority of the duration of `rails new`.