In RHEL 5, yum cannot find a package (python-devel)
Solution 1:
Okay, we contacted Red Hat Support and got an answer.
The python-devel package is in the RHEL Desktop Workstation sub-channel ("rhel-i386-client-workstation-5"), which was not enabled.
By default, the main channel ("core components", "rhel-i386-client-5") is enabled but no sub-channels. By using a web browser and logging in to your Red Hat Network account, you can pull up the record for your system and enable a sub-channel. This process is described in this KnowledgeBase page: http://kbase.redhat.com/faq/docs/DOC-11313