You shouldn't have to use sudo
with gem install ...
. That's what's causing the mismatch between Ruby versions, since root
is using the default installed Ruby, whereas your own account is using RVM's installed version.
Updating the system version of Ruby depends on your operating system, and usually lags behind the very latest version of Ruby. I've been using 2.0 for my latest project I launched last month. I doubt big OS vendors like Ubuntu or Apple are providing that version in their latest distribution. It's best that you manage your own Rubies whenever possible.
To install 1.9.3 you can run:
$ rvm install 1.9.3
then later
$ rvm use 1.9.3