Installing ruby on Ubuntu Gutsy

Just wanted to post my notes on how I was able to install Ruby and Gem
on Ubuntu Gutsy:

$ sudo apt-get install ruby ruby1.8-examples rdoc ri libruby-extras rubygems

$ ruby -v
ruby 1.8.6 (2007-06-07 patchlevel 36) [i486-linux]

$ gem -v
/usr/bin/gem:23: uninitialized constant Gem::GemRunner (NameError)

$ sudo ruby -i.bak \
  -lne 'print "require \047rubygems/gem_runner\047" \
  if /^require /; print' /usr/bin/gem

$ gem -v
1.0.1

$ sudo gem update --system

Thanks to these two posts:

http://www.ruby-forum.com/topic/136806#608707

http://www.nickpeters.net/2007/12/31/fix-for-uninitialized-constant-gemgemrunner-nameerror/

Regards,
- Robert