Description of problem: The Release: for squashfs-tools is missing a %{?dist} tag. See: http://cvs.fedoraproject.org:80/viewvc/devel/squashfs-tools/squashfs-tools.spec?revision=1.21&view=markup
Disttags are not required. The only requirements are: * unique EVRs across Fedora releases (actually, Koji currently even enforces unique VRs regardless of Epoch), * upgrade paths across releases (EVRs going up from one release to the next, i.e. currently F9 < F10 < Rawhide and F9 updates < F10 updates < Rawhide) and * upgrade paths within releases (EVRs not going backwards). Disttags are just a tool to make that easier to satisfy (but you can still screw it up), there's nothing requiring them.