There is some problem with disk on arm03-packager00.cloud.fedoraproject.org. When I was logged in, the command I was executing failed with I/O error. Root filesystem was remounted read-only. My attempts to further diagnose this failed due to I/O errors as well. Now arm03-packager00 doesn't even accept SSH connections.
Yes, the disk is dying. We will need to get it replaced.
Our replacement drives finally arrived, this is fixed now.