Question

Today I installed JRuby by downloading it, extracting it to /home/james/jruby-1.4.0, and adding the following lines to .bashrc:

export JRUBY_HOME=/home/james/jruby-1.4.0
export PATH=$JRUBY_HOME/bin:$PATH

And then I installed some JRuby gems via jruby -S gem install ...

Jruby works fine, but this seems to have caused two problems:

1. When I try to run a Ruby (not JRuby) on Rails migration, I see:

   Missing the Rails  gem. Please `gem install -v= rails`, update your RAILS_GEM_VERSION setting in config/environment.rb for the Rails version you do have installed, or comment out RAILS_GEM_VERSION to use the latest version installed.
   

2. When I do gem list --local, I only see the gems that I’ve installed for JRuby.

Launching web applications via ruby script/server succeeds without any warnings.

Answer 1

Change your path line in your .bashrc to be like this:

export PATH=$PATH:$JRUBY_HOME/bin

Then your gem command will find the MRI one first.

To invoke the jruby gem command use the -S switch, e.g.

jruby -S gem list --local