$ git clone -n https://src.fedoraproject.org/rpms/frotz.git /var/lib/mock/f45-build-9292-401/root/chroot_tmpdir/scmroot/frotz
Cloning into '/var/lib/mock/f45-build-9292-401/root/chroot_tmpdir/scmroot/frotz'...
$ git fetch origin f12b04e66309e1a4af19ac595b0067dc860b9282:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/frotz
 * [new ref]         f12b04e66309e1a4af19ac595b0067dc860b9282 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f12b04e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild