The -devel subpackage is missing beecrypt-devel, elfutils-devel, and rpm-devel in its Requires. This causes compilation failures in packages that use net-snmp built in a "clean" environment.
This is already fixed and will be pushed out with next update ..
I believe this bug was fixed long time ago, please update your RHEL to version 4.2 or later, if you still use older version.