This is just a followup to the previous message I sent about the test
server. The presto.xml.gz file has become a zero-length file for both
extras and updates because of lack of disk space. Unfortunately,
there's nothing I can do to get this problem fixed until tomorrow.
So for the moment, please run yum with the --disablepresto command-line
option while using it (or disable the presto plugin).
Once again, a huge apology for the inconvenience.
Jonathan