Thanks for pointing this out! Yes, it’s a shape problem on our side.
Maybe changing
File “//anaconda3/lib/python3.7/site-packages/pymc3/distributions/distribution.py”, line 584, in generate_samples
broadcast_shape = np.broadcast(*inputs).shape # size of generator(size=1)
From broadcast to broadcast_distribution_samples may solve the problem. I’ll explore it when I get the chance next week. In the mean time, feel free to open an issue in GitHub.
As for the second problem, it will be much harder to fix consistently