$ git clone -n https://src.fedoraproject.org/rpms/os-autoinst.git /var/lib/mock/f39-build-1997781-43957/root/chroot_tmpdir/scmroot/os-autoinst
Cloning into '/var/lib/mock/f39-build-1997781-43957/root/chroot_tmpdir/scmroot/os-autoinst'...
$ git fetch origin 38dcc48e8f0c9ac3c0462eb6525aaecfa74a70b4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/os-autoinst
 * [new ref]         38dcc48e8f0c9ac3c0462eb6525aaecfa74a70b4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 38dcc48 Update to latest git