ruby-on-rails - 为什么我的 Ubuntu 在明确卸载并安装上一个版本后仍然声称 Ruby on Rails 的版本是 4.0.0？

Question

test@test-VirtualBox:~$ sudo gem uninstall rails
[sudo] password for test: 
Successfully uninstalled rails-4.0.0
test@test-VirtualBox:~$ rails -v
Rails 4.0.0

test@test-VirtualBox:~$ sudo gem install rails -v 3.2.11
[sudo] password for test: 
Successfully installed rails-3.2.11
test@test-VirtualBox:/home$ rails -v
Rails 4.0.0

test@test-VirtualBox:~$ sudo gem uninstall rails -v 4.0.0
INFO:  gem "rails" is not installed

test@test-VirtualBox:~$ sudo gem uninstall rails -v 3.2.11    
You have requested to uninstall the gem:
rails-3.2.11
gmaps4rails-1.5.6 depends on [rails (~> 3.2.1)]
If you remove this gems, one or more dependencies will not be met.
Continue with Uninstall? [Yn]  

为什么？

对于它的值(value)，以下是补充信息。

test@test-VirtualBox:~$ gem list rails
*** LOCAL GEMS ***
rails (4.0.0)
test@test-VirtualBox:~$ 
test@test-VirtualBox:~$ sudo rails -v
Rails 4.0.0
test@test-VirtualBox:~$ rails -v
Rails 4.0.0

gem 文件

# Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
gem 'rails', '4.0.0'

Answer 1

尝试使用这个:

gem install rails # No sudo

我认识的大多数人都在使用 rvm(或 rbenv):https://rvm.io/