$ git clone -n https://src.fedoraproject.org/rpms/sane-backends.git /var/lib/mock/f45-build-35598-696/root/chroot_tmpdir/scmroot/sane-backends
Cloning into '/var/lib/mock/f45-build-35598-696/root/chroot_tmpdir/scmroot/sane-backends'...
$ git fetch origin 31777b40a22e6e6916d55c50e5cfeefa2d212292:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/sane-backends
 * [new ref]         31777b40a22e6e6916d55c50e5cfeefa2d212292 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 31777b4 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild