$ git clone -n https://src.fedoraproject.org/rpms/vdr-tvguide.git /var/lib/mock/f40-build-2044613-48727/root/chroot_tmpdir/scmroot/vdr-tvguide
Cloning into '/var/lib/mock/f40-build-2044613-48727/root/chroot_tmpdir/scmroot/vdr-tvguide'...
$ git fetch origin ba1f6ee8dcab2a5db0a232cee8c22966e4adf1da:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vdr-tvguide
 * [new ref]         ba1f6ee8dcab2a5db0a232cee8c22966e4adf1da -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ba1f6ee Update to 1.3.8