I\'m running Ruby 1.9.1p243 on CentOS, and I decided to install rvm to handle upgrading to 1.9.2 or downgrading to 1.8.7 (whichever turns out to work better for rails3).
I've been struggling with setting default rvm ruby to no avail, until I've tried this:
sudo bash -l -c 'rvm alias create default ruby-1.9.3-p392'
"sudo" is for writing into /usr/local/rvm/config/alias (in my example it would contain "default=ruby-1.9.3-p392")
"bash -l" is to make sure it runs all the scripts (/etc/profile, /etc/bash.bashrc, etc..) of login shell
Your install is as root account. Try this in shell [[ -s "/usr/local/rvm/scripts/rvm" ]] && . "/usr/local/rvm/scripts/rvm"
before rvm switch operation. I add this line in my profile file and now all is ok.
Can be a problem of Terminal and you should try to close your Terminal's window and to open new one. :) Try again to see if it has changed...
Typically rvm support is easiest via IRC (#rvm on freenode) - in this particular case, what does running "type rvm | head -n1" show? it should show "rvm is a function". If not, that means the line to source rvm isn't being run correctly and hence switching doesn't work. Typically this means you either have a return in your ~/.bashrc or you missed adding the line to source rvm.
Just came across the same problem.
Instead of appending the following script to ~/.bash_profile, append it to ~/.bashrc:
[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # This loads RVM into a shell session.
And then restart the terminal.