问题
In a rails Gemfile, does gem 'capistrano' need to be inside the :development group or this there any advantage in putting it inside an arbitrary group like :tools?
回答1:
Simply put, no, it doesn't need to be, but it's good for the sake of best practices and keeping your gemsets uncluttered. The best way to do that is open for debate, but basically as long as Capistrano is available to you in the environment you're working in, it doesn't matter what groups it is or isn't associated with, though I can see little to no advantage of using an arbitrary :tools group since :development will exclude it in production cleanly and "auto-magically" in the first place.
来源：https://stackoverflow.com/questions/15661159/does-capistrano-need-to-be-in-the-development-group-in-the-gemfile