$ git clone -n https://src.fedoraproject.org/rpms/vdr-tvguide.git /var/lib/mock/f42-build-3458013-45512/root/chroot_tmpdir/scmroot/vdr-tvguide
Cloning into '/var/lib/mock/f42-build-3458013-45512/root/chroot_tmpdir/scmroot/vdr-tvguide'...
$ git fetch origin b46b00cbf12c5a97aa5920bfa35c7ddd1edc53d5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vdr-tvguide
 * [new ref]         b46b00cbf12c5a97aa5920bfa35c7ddd1edc53d5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b46b00c Rebuilt for new VDR API version 2.7.4