Preserving JRuby gems between upgrades

When installing one of JRuby's frequent upgrades, I need to re-install my gems, as they normally reside in the jruby install directory.

I know it doesn't have to be this way. Could someone post some instructions or point to a web page on how to avoid this?

Keep in mind, I'm not wanting to share gems with a C-Ruby install. Just share between JRuby installs.

Thanks,

From stackoverflow

• 1. Add directory tree <your preferred location>/jrubygems/lib/ruby/gems/1.8
  2. Add directory tree <your preferred location>/lib/ruby
  3. Add directory tree <your preferred location>/lib/site_ruby/1.8

  Add to your .bashrc:

  export GEM_HOME=<your preferred location>/jrubygems/lib/ruby/gems/1.8

  export RUBYLIB=<your preferred location>/lib/ruby:<your preferred location>/lib/site_ruby/1.8