$ git clone -n https://src.fedoraproject.org/rpms/xsc.git /var/lib/mock/f45-build-39136-732/root/chroot_tmpdir/scmroot/xsc
Cloning into '/var/lib/mock/f45-build-39136-732/root/chroot_tmpdir/scmroot/xsc'...
$ git fetch origin 78b9d51ff7520ebfa8bbf8747caa8c058acb2232:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xsc
 * [new ref]         78b9d51ff7520ebfa8bbf8747caa8c058acb2232 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 78b9d51 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild