$ git clone -n https://src.fedoraproject.org/rpms/vtk.git /var/lib/mock/f40-build-735131-106204/root/chroot_tmpdir/scmroot/vtk
Cloning into '/var/lib/mock/f40-build-735131-106204/root/chroot_tmpdir/scmroot/vtk'...
$ git fetch origin 3b88f3fa847bf8fb62b92a1ee4883ca1d6d54599:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vtk
 * [new ref]         3b88f3fa847bf8fb62b92a1ee4883ca1d6d54599 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3b88f3f Rebuild for openslide 4.0.0