What's up with yum?

[Neal D. Becker]

I wanted to try out the baseline yum conf, so after updating to
yum-2.1.10-3, I moved /etc/yum.conf.rpmnew -> /etc/yum.conf.  But when I
run yum update, I get:

sudo yum update
not using ftp, http[s], or file for repos, skipping -

You have enabled checking of packages via GPG keys. This is a good thing.
However, you do not have any GPG public keys installed. You need to download
the keys for packages you wish to install and install them.
You can do that by running the command:
    rpm --import public.gpg.key
For more information contact your distribution or package provider.

I can deal with the gpg keys part, but what's up with the first message?  It
looks to me that it isn't reading /etc/yum.repos.d/ files.  Running

yum -d 10 update is no more informative.