Ruby Gem Install Error: /usr/bin/ruby extconf.rb can't find header files for ruby

I ran into a error when installing the first gem on a CentOS development server I was creating. The error states that the extconf.rb file could not the header files. Below I show the output of the error along with what was done to resolve the error.

Error Installing Ruby Gem:

[root@dev rubygems-1.3.7]# gem install ruby-lsapi
Building native extensions. This could take a while...
ERROR: Error installing ruby-lsapi:
ERROR: Failed to build gem native extension.
/usr/bin/ruby extconf.rb
can't find header files for ruby.
Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/ruby-lsapi-4.0 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/ruby-lsapi-4.0/ext/lsapi/gem_make.out

As you can see above the gem failed to install. The reason is that I had not yet installed the ruby-devel package which is needed during the gem compilation process. After installing ruby-devel as shown below the gem installed without issue.

Install ruby-devel On CentOS Linux:

[root@dev src]# yum install ruby-devel
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* addons: mirrors.xmission.com
* base: centos.mirror.facebook.net
* extras: mirrors.netdna.com
* updates: mirrors.versaweb.com
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package ruby-devel.i686 0:1.8.6.111-1 set to be updated
--> Finished Dependency Resolution
Dependencies Resolved
====================================================================================================================================
Package Arch Version Repository Size
====================================================================================================================================
Installing:
ruby-devel i686 1.8.6.111-1 ruby 533 k
Transaction Summary
====================================================================================================================================
Install 1 Package(s)
Upgrade 0 Package(s)
Total download size: 533 k
Is this ok [y/N]: y
Downloading Packages:
ruby-devel-1.8.6.111-1.i686.rpm | 533 kB 00:01
Running rpm_check_debug
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
Installing : ruby-devel 1/1
Installed:
ruby-devel.i686 0:1.8.6.111-1
Complete!
[root@dev src]#

After installing ruby-devel using the Yum Package Manager you can install the gem, which in this case was ruby-lsapi, without issue as shown in the below example output.

Install ruby-lsapi Gem Without extconf.rb Header Files Error: