How can I downgrade from ruby 1.9.1 to ruby 1.8.7

I just upgraded to rails 3 but was running ruby 1.9.1 prior开发者_运维知识库 to the upgrade. Rails 3 doesn't support Ruby 1.9.1. How can I downgrade to ruby 1.8.7?

This will downgrade from your current version to 1.8.7:

gem update --system 1.8.7

install rvm, this will allow you to run multiple versions of ruby and switch between them at will: rvm

As others have mentioned, its hard to come up with exact solution, in general to downgrade or switch versions for a user:

1. Install Ruby 1.8.7 (or locate it on your system if you have it already)

2. Edit your .bash_profile or .bashrc file to update your $PATH so that the 1.8.7 executable is found first. Something like this:

   export RUBY_187_HOME='/path/to/1.8.7'
   export PATH=$RUBY_187_HOME/bin:$PATH
   

3. This is a little similar to what RVM does and it works.

4. To test, try

   $ which ruby 
   $ /path/to/1.8.7/bin/ruby