[munificent]

> Isn't this a simple instruction you give students in the very first class like "before you submit your homework, restart R session, and make sure your submission runs in the new session"? This only requires them to click a menu item (Restart R session), and a button (Knit or Source or something).

It's the nature of learners to make mistakes. The more things they have to remember to do, the less cognitive power they'll have to focus on what they're trying to learn.

[cheriot]

That's a good point, though in this case the thing they need to remember is a key part of doing the job. Seeing a line of code run correctly once does not mean it's correct. It's one of those concepts that comes up in many forms.

Perhaps one way to make a teachable moment of it is to help them set up a baby CI environment. Then every time it catches something the value of good practices is driven home.

[minimaxir]

That demand is the equivalent of pressing two buttons. (and yes, in my stats course as an undergrad I was also requested to reload and rerun R sessions to ensure code was correct)