$ git clone -n https://src.fedoraproject.org/rpms/rear.git /var/lib/mock/f42-build-3530702-46321/root/chroot_tmpdir/scmroot/rear
Cloning into '/var/lib/mock/f42-build-3530702-46321/root/chroot_tmpdir/scmroot/rear'...
$ git fetch origin 3c6702410435b0d7f6b20de3ba559059ee51b8ce:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rear
 * [new ref]         3c6702410435b0d7f6b20de3ba559059ee51b8ce -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3c67024 Update ppc64le dependencies for bin-sbin merge