What does rails new --dev do? What about rails new --edge?

Question

So I heard about this recently but I'm not sure what it means. It's supposed to "Setup the application with Gemfile pointing to your Rails checkout" but what does that mean exactly? What Rails checkout? I can't seem to find anything else out there explaining this further.

Also, how to you use rails new --edge? Can you just give it the url to a git repository and use that to bootstrap your application?

Answer 1

--dev uses your locally checked-out Rails repository to create the app. --edge will use the latest stable version from the Github repository, instead of from your locally installed Rails gem.

Answer 2

Your rails checkout means a folder on your computer where you have cloned the rails git repository. This would be useful if you wanted to work on changes to rails itself.

edge will use the master branch of the rails GitHub repository.