It looks like something is broken with Fedora mirrors. http://dl-tier1.fedoraproject.org/pub/fedora/linux/development/rawhide/Everything/x86_64/os/repodata/ was updated for the last time on 2018-02-20.
Unfortunately, this is because we have not been able to get a Rawhide compose working since then due to all kinds of bugs and changes. Hopefully we'll get one working soon again.
Right. You can follow along on our efforts in #fedora-releng and/or https://pagure.io/dusty/failed-composes/issues
As soon as we have a compose it will be synced out.
Metadata Update from @kevin: - Issue close_status updated to: Upstream - Issue status updated to: Closed (was: Open)