$ git clone -n https://src.fedoraproject.org/rpms/sos.git /var/lib/mock/f40-build-2042080-48499/root/chroot_tmpdir/scmroot/sos
Cloning into '/var/lib/mock/f40-build-2042080-48499/root/chroot_tmpdir/scmroot/sos'...
$ git fetch origin ddfe073d0c3b96ce982c543fe4e9d5da42b3ffa0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/sos
 * [new ref]         ddfe073d0c3b96ce982c543fe4e9d5da42b3ffa0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ddfe073 Update to 4.6.0