You can check for a missing submodule (folder) in your setup script and print helpful advice, but you can't do the same for the large repo: the damage is alread

You can check for a missing submodule (folder) in your setup script and print helpful advice, but you can't do the same for the large repo: the damage is already done by the time you get to print instructions. In this case things are even easier: the submodule is just a backup for the thing that bundler will do anyways when running "bundle install".