[rpm] yum error "Cannot retrieve metalink for repository: epel. Please verify its path and try again" updating ContextBroker

Another possible cause is that your architecture is not supported. I ran into this because I was provided with a CentOS VM, wanted to install EPEL and couldn't for the life of me get it done.

Turns out the VM was CentOS 7 i386, which is an architecture that is apparently no longer supported by EPEL. I guess the only remedy in this case is to reinstall.