$ git clone -n https://src.fedoraproject.org/rpms/gcab.git /var/lib/mock/f45-build-9732-408/root/chroot_tmpdir/scmroot/gcab
Cloning into '/var/lib/mock/f45-build-9732-408/root/chroot_tmpdir/scmroot/gcab'...
$ git fetch origin 9d9bd07aefc485e3e34d270e5a5dd8b9dcb9b051:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gcab
 * [new ref]         9d9bd07aefc485e3e34d270e5a5dd8b9dcb9b051 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9d9bd07 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild