Hi all,

I'm on # cat /etc/redhat-release 
Scientific Linux SL release 5.2 (Boron)

and I'd like to install some yum groups.
So I do yum groupinstall $group and works fine for some:

# yum grouplist
Loaded plugins: kernel-module
Setting up Group Process
Installed Groups:
   Development Libraries
   Editors
   Legacy Software Development
   Mail Server
   Network Servers
   PostgreSQL Database
   System Tools
   XFS
   Yum Utilities
   glite-WN (production - x86_64)

But Development Tools seems to not be installed:
Available Groups:
   Administration Tools
   Authoring and Publishing
   Cluster Storage
   Clustering
   DNS Name Server
   Development Tools
[...]

So, I try to install it:

# yum groupinstall 'Development Tools'
Loaded plugins: kernel-module
Excluding Packages from dag
Finished
Setting up Group Process
Package flex-2.5.4a-41.fc6.x86_64 already installed and latest version
Package gcc-4.1.2-42.el5.x86_64 already installed and latest version
Package redhat-rpm-config-8.0.45-24.el5.noarch already installed and latest version
Package strace-4.5.16-1.el5.1.x86_64 already installed and latest version
[...]
Package cscope-15.5-15.1.el5_3.1.x86_64 already installed and latest version
No packages in any requested group available to install or update


and the group is still under Avaliable Groups....

Any one could help me to understand why this group does not appear as
installed? 

TIA,
Arnau