trivial delaunay example fails

[Ben Abbott]

I've filed a bug report.

        https://savannah.gnu.org/bugs/index.php?34604

I'm not sure if this is a problem local to my OS, my package manager, or 
something I am doing. Can someone try the example below?

x = [0 0 1 1];
y = [0 1 1 0];
tri = delaunay (x, y)

The answer should be ...

tri =

     3     2     4
     2     1     4

However, I'm getting a qhull error (see the bug report for more detail).

Ben