Earlier quoted context omitted.
> Implementing git in rust for fun and education! Also, not having a license file isn't a messy situation, that means “this project is protected under Berne Convention copyright“: the author is the only one holding every rights on the code and every use that is not explicitly allowed is a copyright infringement (unless it's fair use).
"Use" is allowed, redistribution of the original or derivative works is essentially what is not permitted.
But, can you compile it ? I'm not sure… Better ask your lawyer. And what about running the compiled binary ? I don't think you're allowed to do that.