Following Jake VDP's tutorial blog post, I am attempting to plot a dask graph. However, dot_graph plots an empty png. Here is the example. The resulting png file is zero bytes in size. As you can see, there is no exception raised.

Using dask 0.7.5 built from master on OS X 10.11, Anaconda Python 3.5. I've installed graphviz and pydot2 from pip.