Problems installing mysql-gem

I'm trying to install the mysql gem. I have mysql up and running,
everything is up to date through yum in fedora, fc6.

[root@localhost ~]#
[root@localhost ~]# gem install mysql -y
Select which gem to install for your platform (i386-linux)
1. mysql 2.7.3 (mswin32)
2. mysql 2.7.1 (mswin32)
3. mysql 2.7 (ruby)
4. mysql 2.6 (ruby)
5. Skip this gem
6. Cancel installation


Building native extensions. This could take a while...
ERROR: While executing gem ... (Gem::Installer::ExtensionBuildError)
    ERROR: Failed to build gem native extension.

ruby extconf.rb install mysql -y
can't find header files for ruby.

Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/
for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/mysql-2.7/gem_make.out
[root@localhost ~]#
[root@localhost ~]# cat /etc/fedora-release
Fedora Core release 6 (Zod)
[root@localhost ~]#
[root@localhost ~]# date
Sun May 13 08:01:18 BST 2007
[root@localhost ~]#
[root@localhost ~]#