$ git clone -n https://src.fedoraproject.org/rpms/vapoursynth.git /var/lib/mock/f40-build-735815-106480/root/chroot_tmpdir/scmroot/vapoursynth
Cloning into '/var/lib/mock/f40-build-735815-106480/root/chroot_tmpdir/scmroot/vapoursynth'...
$ git fetch origin 75add59a4663160d1ceb7e7bacf803380a7c20a2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vapoursynth
 * [new ref]         75add59a4663160d1ceb7e7bacf803380a7c20a2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 75add59 Update to R65