Qt Session management error with matplotlib.pyplot.plot

Question

All of a sudden, whenever I call matplotlib.pyplot.plot (within a unix OS), the following error is printed to the screen:

Qt: Sessi         


        

Answer 1

Make sure you use "su -" and not just "su"

Answer 2

The answer to the question is, yes, there is a solution that doesn't require editing the sudoers file. I noticed that in the .cache directory of my home directory, there was a matplotlib directory and a sessions directory.

I deleted these.

The problem was resolved.

I remain unsure why the error arose in the first place.