Not really. It's been proved that if your unsafe foundations are correct and don't break the rules (i.e. their precondition is correct), then anything safe buil

Not really. It's been proved that if your unsafe foundations are correct and don't break the rules (i.e. their precondition is correct), then anything safe built on top of that is also correct. Sure you could rely on a C/C++ library that causes problems, but then again you can either: A) fix that library B) replace that part with Rust or even stricter language.