no one has written an OS in Rust that isn't a toy or PoC. theo de raadt made this point in a video, too, where he argues that no new language has come close to replacing C for OS development, and all the userland tools are still written in C.
I don't argue against C++ being suitable for OS development. C++ has been used by NASA to control robots it sends to space. But I don't think Rust has proven itself beyond toy concepts people put on github. C is still king in the land of OS development.
Fridtjof: are you sure it hangs and not exits before you expect? you might be missing a Thread#join but for best results please share what you're working with. describing your problem with words and from your understanding usually doesn't get the answer you want.
is the main thread in a loop? otherwise it'll exit, and the threads you've spawned will die with it.