This is coming from Shelby as a fix for the CentOS gcc compiler error that occurs when you try run a Yum update on some systems:
--> Processing Dependency: glibc-common = 2.3.4-2.25 for package: glibc-dummy-centos-4 --> Finished Dependency Resolution Error: Missing Dependency: glibc-common = 2.3.4-2.25 is needed by package glibc-dummy-centos-4
First you have to remove the existing package:
yum remove glibc-dummy-centos-4
Then you have to reinstall gcc:
yum install gcc & yum install gcc*
Then you should be able to proceed running the yum update command.