A malfunctioning build of perl landed in the rawhide buildroots a few minutes ago. This caused almost every build that started afterward to fail with a mock error 100 (unable to init the build root). I've untagged the bad build of perl and a newRepo task has started that has a better build of perl on it. Once this task (http://koji.fedoraproject.org/koji/taskinfo?taskID=113051 ) is done, you'll need to resubmit your builds for rawhide.
Very sorry for the interruption in service.