Kernel crashes when plotting with `block=True`

[wmvanvliet]

This snippet of code will crash QtConsole:

%matplotlib qt
from matplotlib import pyplot as plt
plt.plot([1, 2, 3, 4])
plt.show(block=True)

The block=True probably interacts badly with the Qt thread spawned by the %matplotlib qt magic. However, this does seem to be a QtConsole issue, as this works fine in a terminal ipython console.

[ccordoba12]

What happens when running that code in jupyter console or JupyterLab? The thing is terminal IPython and Qtconsole/JupyterLab/Jupyter console use different ways to declare event loops, so they can't be compared.