$ git clone -n https://src.fedoraproject.org/rpms/rust-lz4.git /var/lib/mock/f45-build-43087-800/root/chroot_tmpdir/scmroot/rust-lz4
Cloning into '/var/lib/mock/f45-build-43087-800/root/chroot_tmpdir/scmroot/rust-lz4'...
$ git fetch origin e88c8e6095b3d3e3d79bb339436fd4540e889e1d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-lz4
 * [new ref]         e88c8e6095b3d3e3d79bb339436fd4540e889e1d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e88c8e6 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild