Does the student solution remain in their git forever?

Looking at using the autograder feature in git classroom… Question:

Do the student accounts remain active after the course is closed in github? I’m concerned that students will simply clone former students’ solutions to problems and submit them as their own work.

This is a great question, but I don’t think so. If the repository is not public, and allow forking of private repositories is not checked (go to your Classroom > Settings > Member privileges to look), then those repositories that are a part of the class should not be able to be cloned (even if private). I believe this is left unchecked by default, but worth looking.

Another solution might be to archive the course when complete.

A student can always clone a repo locally to many different machines, copy it, push to different remotes, etc.

Probably the spirit of your question is can a student see the GitHub remotes in perpetuity and the answer is that I don’t know. In my case, because I did not know, I cloned all repos locally (via the API) and then deleted old student repos from my GitHub Classroom org.

I’m not sure if this will work differently in classroom, but when you set up an organization you have admin access to all repos within it. I would assume that to cut off access for students you simply need to revoke the student’s access to those repos. Local cloned copies will still will exist on the student’s systems. However the version on github should be controllable.

There are multiple online resources that can give students the answers to any homework. I believe that it is more important to raise awareness of the consequences of cheating and to find the root cause of why students are cheating.
A student that cheats only cheats themselves. When they go out to the real world their lack of knowledge will hender their performance.
On the other hand, students that feel that they need to find the answers elsewhere may not have sufficient learning resources, or they have gaps of knowledge that were not fulfilled during lecture. There are so many learning disabilities that are not caught as kids, and adult students may find themselves struggling throughout their college experience.