问题
I've made a fresh installation of Ruby on Rails on my Windows 7 machine (using RailsInstaller) after a failed attempt to follow Michael Hartl's Ruby on Rails Tutorial (if you're interested, see my previous question pertaining to the said fail).
As I thought my previous fail had something to do with my inept attempt at installing different gem versions hoping to replicate requirements laid out in the tutorial, I decided to check the version of rails gem immediately after the install.
When I typed
rails -v
I got Rails 4.0.2 as a response, but when I did
gem list
it said rails (3.2.16), and that got me really confused.
Are we talking about two different things here?
Mind you that this is a crisp install: these two commands were the first, and the only two commands I ever typed.
Can this be the reason I couldn't boot WEBrick for my sample project?
Thanks!
回答1:
The reason you are seeing this is the Railties executable wrapper is still installed. You need to uninstall the Rails gem and and the Railties gem.
$ gem uninstall rails
$ gem uninstall railties
You will likely be prompted to select which version of the gem to uninstall.
If needed, you can reinstall a specific version of Rails.
$ gem install rails -v 3.2.16
$ gem install railties -v 3.2.16
回答2:
gem list will show all gems you've installed. If you have multiple versions of rails installed it will show them.
来源：https://stackoverflow.com/questions/20830622/im-confused-rails-v-and-gem-list-show-different-versions