$ git clone -n https://src.fedoraproject.org/rpms/lem.git /var/lib/mock/f45-build-15668-478/root/chroot_tmpdir/scmroot/lem
Cloning into '/var/lib/mock/f45-build-15668-478/root/chroot_tmpdir/scmroot/lem'...
$ git fetch origin 12c8f905a4e067fe31f1e55d3667b6e93b335662:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/lem
 * [new ref]         12c8f905a4e067fe31f1e55d3667b6e93b335662 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 12c8f90 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild