Why does 'bundle' install production gems

问题:

Gemfile says:

gem 'sqlite3', :groups => [:development, :test]
gem 'mysql2', :group => :production

yet when I type bundle install on my development machine ALL gems are installed.

What's wrong with my setup?

回答1:

The point of Bundler is to create a consistent gem environment across deployments. Gems, unfortunately, can interact even if they aren't loaded or required. So for maximum consistency, all gems should be installed, even if they aren't all required.

However, if you don't want all gems installed all the time, you can use the bundle install --without option.