Can that be taught in a classroom? There are various strategies and tricks one can use, but I think it's better to learn that skill "in the field" than out of a textbook.
It'd be interesting to see a course where you're given a large open-source project (say, Chromium or Linux or Postgres) and your task is to make & submit a small change in the codebase to implement some plain-language user request. The instructor would then walk you through how to download the project, read developer documentation, and build it; how to identify the relevant portion of the codebase, and everything else that your change might affect; how to match coding style & conventions; how to run tests; and how to submit a patch to the maintainers in a way that is likely to get accepted. Reading code is a real skillset, and being able to quickly grok & modify an unfamiliar codebase is a huge leg up in many jobs. Bonus points if the homework assignments for this course are real bug reports, so you end up contributing to open source for class credit.
Universities do have courses that require contributing to an Open Source project. I saw this when working on Servo a couple years ago. I was disappointed in the students. The average university student is not very motivated.
If the course is an elective it's probably better (more motivated students).
One might argue that sounds like software engineering, and that's mostly a separate activity from both programming and from computer science. Of course they overlap.
However, I assert that something like 95% of computer science graduates are actually going to work as software engineers, not as computer scientists. So actually teaching some of that would not be amiss...
I’ve heard of several universities in the UK running this kind of course.
I took a class aimed at teaching us to read scientific papers. Seems like sort of the same situation: lots of “tips and tricks”, but also a skill that needs practice. The class I took essentially brain dumped the tips and tricks part in the first week, then spent the rest of the semester practicing reading papers and pulling insights out of them. The same approach could be used for a class about reading code.