$ git clone -n https://src.fedoraproject.org/rpms/realtime-setup /var/lib/mock/f41-build-side-1-3137698-39796/root/chroot_tmpdir/scmroot/realtime-setup
Cloning into '/var/lib/mock/f41-build-side-1-3137698-39796/root/chroot_tmpdir/scmroot/realtime-setup'...
$ git fetch origin b1fd8cb2389859db3e54c8706620a32672f7b1c4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/realtime-setup
 * [new ref]         b1fd8cb2389859db3e54c8706620a32672f7b1c4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b1fd8cb uploaded new source