rails -v errors when setting up rvm

I am trying to set up an environment as per this tutorial http://railstutorial.org/book#sec:1.2.2.3开发者_运维百科 however I get the below error when running 'rails -v'

bash-3.2$ rails -v
/Users/sandbox1/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/rubygems.rb:762:in `report_activate_error': Could not find RubyGem rails (>= 0) (Gem::LoadError)
        from /Users/sandbox1/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/rubygems.rb:219:in `activate'
        from /Users/sandbox1/.rvm/rubies/ruby-1.9.2-p0/lib/ruby/1.9.1/rubygems.rb:1065:in `gem'
        from /usr/bin/rails:18:in `<main>'

Has anyone had this before?

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Incase anyone else has this problem and the marked answer doesn't solve it, here is what fixed it for me:

Don't use sudo.

• "When you do sudo you are running commands as root, another user in another shell and hence all of the setup that RVM has done for you is ignored while the command runs under sudo (such things as GEM_HOME, etc...). So to reiterate, as soon as you 'sudo' you are running as the root system user which will clear out your environment as well as any files it creates are not able to be modified by your user and will result in strange things happening. (You will start to think that someone has a voodoo doll of your application...)"

Taken from here

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resolved by running "rvm gemset update"