$ git clone -n https://src.fedoraproject.org/rpms/sil-gentium-fonts.git /var/lib/mock/f45-build-35967-700/root/chroot_tmpdir/scmroot/sil-gentium-fonts
Cloning into '/var/lib/mock/f45-build-35967-700/root/chroot_tmpdir/scmroot/sil-gentium-fonts'...
$ git fetch origin a68fa4c29308ffa74f4c5e590445a9dd751dc661:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/sil-gentium-fonts
 * [new ref]         a68fa4c29308ffa74f4c5e590445a9dd751dc661 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a68fa4c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild