I’m updating to Ruby 1.8.6 on the Fluffy QA Site.
It’s operational CentOS 5 final.  (cat /etc/redhat-release)
I added the following yum repository:
[ruby]

name=ruby

baseurl=http://repo.premiumhelp.eu/ruby/

gpgcheck=0

enabled=0



Then I ran:
 yum –enablerepo=ruby install ruby ruby-devel rubygems ruby-docs ruby-ri ruby-irb ruby-rdoc
I don’t know the quality of this repository, so don’t take it as my endorsement.  I found it on the internet via google which turned up this suggestion on a mailing list.
Most likely the Ruby version supplied by doing an rpm update on the official Centos 5 repository would’ve been fine, Ruby 1.8.5-5.el5_2.3
– note, I’m actually going back to to the official Ruby installation because of the fact that there's a security vulnerability here:
http://www.securitytracker.com/alerts/2008/Jul/1020476.html
Rather than rip it out by the roots as well as installing the correct RPMs by force, I found a cool package:  yum-allowdowngrade:
yum list available ruby*

Loading “allowdowngrade” plugin

Loading “installonlyn” plugin

Setting up repositories

Reading repository metadata in from local files

Available Packages

ruby.i386                                1.8.5-5.el5_2.3        updates

ruby-devel.i386                          1.8.5-5.el5_2.3        updates

ruby-docs.i386                           1.8.5-5.el5_2.3        updates

ruby-irb.i386                            1.8.5-5.el5_2.3        updates

ruby-libs.i386                           1.8.5-5.el5_2.3        updates

ruby-mode.i386                           1.8.5-5.el5_2.3        updates

ruby-rdoc.i386                           1.8.5-5.el5_2.3        updates

ruby-ri.i386                             1.8.5-5.el5_2.3        updates

ruby-tcltk.i386                          1.8.5-5.el5_2.3        updates
yum grouplist
yum groupremove “Ruby”
yum “groupinstall “Ruby”
yum remove ruby-libs ruby-docs
yum install ruby-libs ruby-docs
yum install ruby-irb ruby-rdoc ruby-ri
so now my ruby installation looks like:
Installed Packages

ruby.i386                                1.8.5-5.el5_2.3        installed

ruby-devel.i386                          1.8.5-5.el5_2.3        installed

ruby-docs.i386                           1.8.5-5.el5_2.3        installed

ruby-irb.i386                            1.8.5-5.el5_2.3        installed

ruby-libs.i386                           1.8.5-5.el5_2.3        installed

ruby-mode.i386                           1.8.5-5.el5_2.3        installed

ruby-rdoc.i386                           1.8.5-5.el5_2.3        installed

ruby-ri.i386                             1.8.5-5.el5_2.3        installed
The reason I wanted to upgrade to 1.8.6 was to get the 1.9 warnings, as well as to retain consistent with windows.  I’ll still utilize 1.86 on Linux VMs not facing the internet, but not on QA Sites.
rubygems 1.1.1 was installed by hand.