$ git clone -n https://src.fedoraproject.org/rpms/lz4.git /var/lib/mock/f41-build-side-1-2658247-28541/root/chroot_tmpdir/scmroot/lz4
Cloning into '/var/lib/mock/f41-build-side-1-2658247-28541/root/chroot_tmpdir/scmroot/lz4'...
$ git fetch origin 3a08b19b5d1a69c31b995cc9988c2d87a5578a6f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/lz4
 * [new ref]         3a08b19b5d1a69c31b995cc9988c2d87a5578a6f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3a08b19 update to 1.10.0 rhbz#2299256