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