Задание pre-push не работает, если в глобальных настройках git'а init.defaultBranch установлен на main, так как setup.sh выполняет git push -u origin master. Решается очень просто, например можно добавить заметку об этом в pre-push/README.md, а то через год мб побольше людей перейдет на main вместо master.

Unfortunately, in the git attributes task the second link (https://www.freepngimg.com/download/temp/20698-7-mario-transparent-background_400x400.png) doesn't work any more..

Maybe, for example, this one will do?
Or this one

Слайд 2 лекции про LLVM:

LLVM = Low Level Virtual Machine

llvm.org:

Despite its name, LLVM has little to do with traditional virtual machines. The name "LLVM" itself is not an acronym; it is the full name of the project.

It seems some lectures use material from "The Missing Semester of Your CS Education" MIT course, compare e.g. Git lecture notes: https://missing.csail.mit.edu/2020/version-control/ vs. current version in this repo.

If so, I think they should be properly referenced and credited at the very least (the original is licensed as CC BY-NC-SA).