$ git clone -n https://src.fedoraproject.org/rpms/stellarium.git /var/lib/mock/f39-build-2092018-50235/root/chroot_tmpdir/scmroot/stellarium
Cloning into '/var/lib/mock/f39-build-2092018-50235/root/chroot_tmpdir/scmroot/stellarium'...
$ git fetch origin 4a6dd0cbf2c94d7da0a9caaa6bea047b6807b998:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/stellarium
 * [new ref]         4a6dd0cbf2c94d7da0a9caaa6bea047b6807b998 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4a6dd0c 23.3