Examples crash MacOS session (hard logout)


I tried the examples in flatland 2.0 on a fresh checkout and the examples crash my MacOS session, that is, the screen turns black and then the MacOS login screen appears.
I am working with the latest Mojave OS and anaconda, using Python 3.7.4

Packages installed according to requirements_continuous_integration


The crash does not seem to originate directly from the rendering. The crash also occurs when all rendering is commented out.

To reproduce:
> cd examples
> python training_example.py

2019-10-07 11:31:23.717 python[16961:625762] HIToolbox: received notification of WindowServer event port death.
2019-10-07 11:31:23.717 python[16961:625762] port matched the WindowServer port created in BindCGSToRunLoop

It seems that only the MaOS window server crashes: after logging in again, the terminal session is still running!

Update 2:
The same crash occurs with all other examples in the examples folder, including flatland_2_example

Update 3
The issue is caused by the following bug in matplotlib/Tkinter


  1. Downgrade Python to 2.7.0
  2. Downgrade matplotlib to 3.0.3


1 Like

Another option is to downgrade the version of Tkinter to 8.6.7 while keeping Python3 and Matplotlib;

conda install -c conda-forge ‘tk==8.6.7’


See also this discussion: http://gitlab.aicrowd.com/flatland/flatland/issues/90#note_21238