Crashes python when using the '-c' flag

[apal90]

I used triangle to make a triangulation of a rectangle (here, a square), using just the four corner points:

## make boundary of sheet
xyRectangle = np.array(((-1,-1), (-1,1), (1,1), (1,-1)))

## make triangulation
xy0 = xyRectangle 
A = dict(vertices=xy0)
B = tr.triangulate(A, 'qa0.0003')
tr.compare(plt, A, B)
plt.show()

When I use only the q or a flags, it runs perfectly. However, when I try calculating the convex hull as well, using the c flag, it just crashes my Jupyter notebook kernel.

Is there some bug somewhere, or am I not using the flag correctly?