$ git clone -n https://src.fedoraproject.org/rpms/xarchiver.git /var/lib/mock/f42-build-side-1-3502136-45977/root/chroot_tmpdir/scmroot/xarchiver
Cloning into '/var/lib/mock/f42-build-side-1-3502136-45977/root/chroot_tmpdir/scmroot/xarchiver'...
$ git fetch origin 46cb203e980b45ae7559a737f325ed8cde91f81d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/xarchiver
 * [new ref]         46cb203e980b45ae7559a737f325ed8cde91f81d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 46cb203 Update to 0.5.4.25 (rhzb#2354300)