Unfortuntely, that doesn't answer the question of where to get the correct version of glibc-devel. RedHat 7.0 ships with glibc-2.1.92, and the current update for RedHat 7.0 is glibc-2.2-12. The version 2.2-9 which is included with e-smith appears to have been a previous update, which was superseded by 2.2-12. I don't know whether it'd be safe/advisable to install glibc-devel-2.2-12 without also upgrading glibc.