Rails keeps telling me that it's not currently installed
Solution 1:
If you're running a rails command immediately after installing rails, you will need to restart your terminal before your commands will be recognized.
Solution 2:
I had this problem today. Not completely related to your question, but since this page is what comes up in Google when I search for "Rails is not currently installed on this system", I thought I would add my answer:
What happened is that I was using ruby 1.9.2 with rails for a while, but then I needed to use ruby 1.8.7 to run some other script that I found.
Afterwards, I wanted to change by system back to using 1.9.2, and that's where the problem started:
$ rvm list
=> ruby-1.8.7-p352 [ x86_64 ]
ruby-1.9.2-p290 [ x86_64 ]
$ rvm use 1.9.2
I thought that would do the trick. But no, that gives me the "Rails is not currently installed on this system" message.
What I had forgotten is that I had configured rails using an rvm gemset. So I needed to specify the correct gemset when I was selecting which ruby version to make active.
$ rvm gemset list_all
gemsets for ruby-1.8.7-p352 (found in /Users/asgeo1/.rvm/gems/ruby-1.8.7-p352)
global
gemsets for ruby-1.9.2-p290 (found in /Users/asgeo1/.rvm/gems/ruby-1.9.2-p290)
global
rails31
$ rvm use ruby-1.9.2-p290@rails31
That did the trick.