> The fact that the certified toolchain is just the normal, publicly available one is great too.

And speaks to the standards of quality that the project holds itself to.

Yes, Ferrocene is able to be qualified more easily in part by how good upstream development practices are. A lot of qualified compilers need to be written from scratch because the existing compilers do not do testing and other things that are required for qualification, but the upstream Rust project has a development process far closer to a safety qualified compiler than not. It’s something worth celebrating about rust as a project.

> Things like core and std are not part of the current certification package

As with C++ I'm not sure this makes coherent sense because of the relationship between the language and some elements of the supporting libraries - with respect to `core` specifically, the Rust programming language requires some of core.

Suppose you write a for loop. In Rust that's just sugar, and it's de-sugared into a loop that uses IntoIterator::into_iter, Iterator::next, Option::Some and Option::None which are all from the core library.

Hence the warning. They're not separable, but it's what the current state of the offering is. If you ship core anything depending on core or std, the burden is on you to ensure those parts of your code are appropriately qualified until they can get the situation sorted.