$ git clone -n https://src.fedoraproject.org/rpms/calf.git /var/lib/mock/f45-build-3977-329/root/chroot_tmpdir/scmroot/calf
Cloning into '/var/lib/mock/f45-build-3977-329/root/chroot_tmpdir/scmroot/calf'...
$ git fetch origin 2710c97d6914263ae85123aabcaff72f2f1c63d9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/calf
 * [new ref]         2710c97d6914263ae85123aabcaff72f2f1c63d9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2710c97 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild