Someone else's mention of livna issues made me realize the cause of a problem.  When trying to get a source rpm yumdownloader was failing as follows:

yumdownloader --destdir /home/mike/src/selinux/audit --source audit

Enabling livna-source repository
Could not retrieve mirrorlist http://rpm.livna.org/mirrorlist-source error was
14: PYCURL ERROR 7 - ""
Cannot retrieve repository metadata (repomd.xml) for repository: livna-source. Please verify its path and try again

Setting enabled=0 in /etc/yum.repos.d/livna.repo resulted in yumdownloader working.

It seems odd that yumdownloader should fail with an error for a repo that was not required for the package in question.

Even stranger, this problem occurs with enabled=1 under [livna] and enabled=0 under [livna-source]

Mike