[cperciva]

I've heard stories about a professor who wanted to teach his students to write portable code and announced that he would test their programs on one of <insert long list of UNIX systems> but he wasn't going to tell them which.

Does that sound familiar? It might be pure apocrypha.

[cat-dev-null]

Yup. In undergrad lower-division courses, we were explicitly informed of this and tradeoffs of proprietary toolchain features. And, most lectures / graders / readers followed through. They had a custom hand-in system on the student-side and then their own scripts to run batches of student builds wherever they chose. Some courses wanted Makefiles, others wanted things like "build.sh" and "run.sh".

BTW: The uni also claimed (unverified, could be an empty threat) a multi-institution (Berkeley, Stanford, MIT, etc.), code plagiarism detection system covering two decades of coursework. (Maybe MOSS.)