That "it's too immature" is a great, dismissal line given it's incredibly important for choosing a language to write a safe/secure kernel in. My choice against it as main language would be due to lack of assurance technology made for it. With C subset and/or SPARK Ada, I have a pile of tech from formal specifications to static analysis to test generators to assembly certifiers. Add powerful IDE's & ecosystem to it. Then, even if people don't want that, there's regular compilers for what I produce on countless platforms for increased usage opportunities and extra security through hardware diversity/obfuscation. Rust doesn't give me all this. Not just "immature:" nobody working on most of it at all or with enough effort I know it will be there in 1-3 years when I need it.

That said, I love and encourage your work on Redox plus these other Rust-based kernels. There's no reason to gripe about them that I see. The posts are good for learning like most kernel dev w/ extra language & safety content on the side. You Redox devs in particular are really rolling on it being safe & practically usable. There's just that the gap between what's achievable on high end with Rust and C/SPARK is the size of the grand canyon. Many PhD's worth of work.