$ git clone -n https://src.fedoraproject.org/rpms/xscreensaver.git /var/lib/mock/f45-build-39118-732/root/chroot_tmpdir/scmroot/xscreensaver
Cloning into '/var/lib/mock/f45-build-39118-732/root/chroot_tmpdir/scmroot/xscreensaver'...
$ git fetch origin f7252ea77e96c66070426ae790569de9b82487f7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xscreensaver
 * [new ref]         f7252ea77e96c66070426ae790569de9b82487f7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f7252ea Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild