it will create all the necessary files and run in the end
bundle install
You might want --skip-bundle, if you know that you are going to add some other gems to the default stack. Matthew is adding ‘monban’ etc. so just to save some time he skips the initial default bundle install.
When he adds all the gems(saves the Gemfile) he runs
bundle
Which is a shorthand for
bundle install
For him the :assets group did not install, so he ran
bundle --without foo
–without is used when you don’t want specific category installed. A common thing that you don’t want :assets in your production server(because your compile them on your machine and deploy them precompiled).
–without remembers the last option. For him it was set for --without assets, he overrode it to --without foo
If you look at the video at 3:57 when he runs --without foo the gems sass, sass-rails from the :assets group are added.
Hopefully this explain it.
P.S Rails 4.0 removed the assets group from Gemfile.