Which Ruby version am I really running?

Question

I'm running Ubuntu 12.04 LTS, and installed Ruby via RVM.

The problem is, when I type ruby -v into the terminal, it says that my Ruby version is 1.8.7, and using the shotgun gem for Sinatra also says that I'm running Ruby 1.8.7.

But when I type rvm list it shows that the only version of Ruby that I have installed is 2.0.0 and it is my current and default version.

I installed Ruby 2.0.0 via RVM and it is the only version I had installed on my machine.

Now when I tried to install Rails 4 but got an error saying that I need Ruby 1.9 or higher.

How do I know what version am I really on, and how do I set 2.0.0 as my only version?

Answer 1

On your terminal, try running:

which -a ruby 

This will output all the installed Ruby versions (via RVM, or otherwise) on your system in your PATH. If 1.8.7 is your system Ruby version, you can uninstall the system Ruby using:

sudo apt-get purge ruby 

Once you have made sure you have Ruby installed via RVM alone, in your login shell you can type:

rvm --default use 2.0.0 

You don't need to do this if you have only one Ruby version installed.

If you still face issues with any system Ruby files, try running:

dpkg-query -l '*ruby*' 

This will output a bunch of Ruby-related files and packages which are, or were, installed on your system at the system level. Check the status of each to find if any of them is native and is causing issues.