Otter-grader's export function fails if a warning is raised for code in a manually-graded section

[NSagan271]

Bug description

We have a lab where some plotting code in a manually-graded section raises a warning. When we then run grader.export(run_tests=True), the cell throws a RuntimeError and doesn't generate the submission .zip file.

The line that it's failing on is:

if results.stderr:
    raise RuntimeError(results.stderr)

which makes it seem like this is expected behavior. However, when I search online, I keep on seeing that otter-grader is supposed to ignore warnings.

Also, when I tried locally (running otter version 4.2.1), I didn't have this issue. So maybe it's an issue with the version that the EECS hub is using (and will be fixed by #4495, hopefully) but I'm not sure.

We suppressed the warning with warnings.filterwarnings("ignore", message="Badly conditioned filter coefficients") for now, but I'm putting this here so it's on your radar.

Environment & setup

• Hub: EECS Hub
• Language: Python

How to reproduce

1. Go to https://eecs.datahub.berkeley.edu/hub/user-redirect/git-pull?repo=https%3A%2F%2Fgithub.com%2FEE120-Course-Staff%2Flab-controls&urlpath=tree%2Flab-controls%2Flab5-controls.ipynb&branch=main
2. Comment out warnings.filterwarnings("ignore", message="Badly conditioned filter coefficients")
3. Ask me for the solutions on slack, and copy them over to the notebook. Run all cells.
4. grader.export should fail.