$ git clone -n https://src.fedoraproject.org/rpms/sos.git /var/lib/mock/f41-build-side-1-2816633-32973/root/chroot_tmpdir/scmroot/sos
Cloning into '/var/lib/mock/f41-build-side-1-2816633-32973/root/chroot_tmpdir/scmroot/sos'...
$ git fetch origin 0679c75cc08791d2b2d60224718464307c5b2325:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/sos
 * [new ref]         0679c75cc08791d2b2d60224718464307c5b2325 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0679c75 Rebased on upstream 4.8.0