September 2018

Override the URL patterns (`urls.py`) in a Django test to inject a test-only view — use `@override_settings(ROOT_URLCONF=...)`.

Avoid `table already exists` failures in Django tests when running with `--keepdb` after cancelling migrations — how to forcibly reset the test DB migration state.

Django: Best way to unit-test an abstract model - Stack Overflowhttps://stackoverflow.com/questions/4281670/django-best-way-to-unit-test-an-abstract-model

Use a lambda callback with Python's `re.sub` to replace only a captured group (e.g. a version number) inside a larger pattern.

MultiViews is enabled

When you start samba-ad-dc using the command `$ sudo systemctl start samba-ad-dc`, and check either /var/log/samba/log.smbd or /var/log/samba/%m, it appears that port 53 is unavailable.

Apache suddenly crashes, and upon checking the logs, I found the following messages: "AH00050: Child 7815 returned a Fatal error... Apache is exiting!" and "AH02818: MPM run failed, exiting."

When `do-release-upgrade` to Ubuntu 18.04 hangs on libnih1 or upstart packages, here is how to unstick and complete the release upgrade.