All packages fail to build since about 12:30 UTC, Dec 8.[[BR]] The reason given is always (the task id varies, of course):
[Errno 30] Read-only file system: '/mnt/koji/work/tasks/3653'
http://koji.fedoraproject.org/koji/
Yes, this is an unplanned issue with the nfs server. ;(
It's running a fsck now, and hopefully will be back up soon.
Sorry for the trouble.
Further updates in https://fedorahosted.org/fedora-infrastructure/ticket/3058
Thanks for the ticket.