How to create a new rails app from existing source?

I saw somewhere not long a开发者_高级运维go that in 3.0.4 or 3.0.5 there is ability to do something like that:

rails new myapp -m https://git@github.com:user/app_template_repo.git

to make the new application from the existing sources in git repository, but I can't find the exact command right now. Could anyone help?

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git clone https://git@github.com:user/app_template_repo.git