$ git clone -n https://src.fedoraproject.org/rpms/graphviz.git /var/lib/mock/f41-build-836620-158883/root/chroot_tmpdir/scmroot/graphviz
Cloning into '/var/lib/mock/f41-build-836620-158883/root/chroot_tmpdir/scmroot/graphviz'...
$ git fetch origin 68da26aaf0ef265c9d542543df611f526917d4b2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/graphviz
 * [new ref]         68da26aaf0ef265c9d542543df611f526917d4b2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 68da26a Build with guile 3.x