[returningfory]

The article says:

> While these checks could also be handled by unit tests, most scientists generally just end up with their own weird set of ad hoc test outputs and print statements. It’s ugly, and not infallible, but it tends to work well given the intensive nature of our result-testing behaviour and community cross-checking.

The sense in which this statement is plainly wrong is actually addressed in the original article:

> Regressions like that are common when working on a complex piece of software, which is why industrial software-engineering teams write automated regression tests.

This is the whole point. You can only run your "ad hoc" print-statement-based tests once off, which is why such "tests" are useless for finding regressions.