systemd.journal not imported correctly by lpci runner when running pylint via pre-commit hook

[Tim Andersson]

We [5] started having CI failures (I'm not sure exactly when) with this error [1]:

:: charms/focal/autopkgtest-cloud-worker/autopkgtest-cloud/worker/worker:33:0: E0611: No name 'journal' in module 'systemd' (no-name-in-module)
:: charms/focal/autopkgtest-cloud-worker/autopkgtest-cloud/worker/worker:33:0: E0401: Unable to import 'systemd.journal' (import-error)
:: charms/focal/autopkgtest-cloud-worker/autopkgtest-cloud/worker/worker:67:26: E1101: Module 'systemd' has no 'journal' member (no-member)

This was not at all reproducible locally, and I checked the pylint paths and made sure the module was correctly installed on the CI runner - it was. I spent a long time trying to debug this, but I eventually just decided to mask the errors with the pylintrc. It's not a big issue and probably something to do with the pylint version - I've seen similar bug reports [2] which seemed to get solved with newer pylint versions, but obviously in the lpci runner we just install the package version for that release (focal in this case - which we have to use as that's what our prod environment is running) and it's a bit finnicky to do otherwise.

For a reproducer, you can clone [3], and checkout [4]. If you push to launchpad as a fork, you'll see the CI failures in the runner, but running lpci run locally you will see no such failures.

[1] https://launchpadlibrarian.net/715605857/buildlog_ci_autopkgtest-cloud_df949e5544820f195b5094b402dd6d0f97a2ef8a_BUILDING.txt.gz
[2] https://github.com/pylint-dev/pylint/issues/5645
[3] https://code.launchpad.net/~ubuntu-release/autopkgtest-cloud/+git/autopkgtest-cloud/+ref/master
[4] df949e5544820f195b5094b402dd6d0f97a2ef8a
[5] Canonical Ubuntu QA/Release Management Team