[CentOS] odd dependency

I'm putting the finishing touches on a new server, which will be replacing
an old one. It's got a non-rpm ruby package (I hear lots of not-nice
things about the RH package). The new server had ruby installed, so I went
to yum remove it.

And it removed ibutils as a dependency of ruby or ruby-libs.

rpm -qi of ibutils tells me
Summary     : OpenIB Mellanox InfiniBand Diagnostic Tools
Description :
ibutils provides IB network and path diagnostics.

On 5.8, it's installed, and ruby isn't. Anyone have any idea why
Infiniband utils should be required for ruby?

        mark