$ git clone -n https://src.fedoraproject.org/rpms/ginga.git /var/lib/mock/f40-build-2652955-66897/root/chroot_tmpdir/scmroot/ginga
Cloning into '/var/lib/mock/f40-build-2652955-66897/root/chroot_tmpdir/scmroot/ginga'...
$ git fetch origin 31dcb75fb8e86692f7a32bba61c146556f8d99c7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ginga
 * [new ref]         31dcb75fb8e86692f7a32bba61c146556f8d99c7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 31dcb75 New upstream source 5.0.0