I like Rust and I'd love to see it in the Linux kernel, but not before the GCC+Rust issues are all fixed. You shouldn't need non-GCC compilers to compile Linux and from what I can tell there isn't any GCC Rust compiler that's fully equivalent to the standard Rust compiler just yet.

They say that Rust support is optional, but when the first big driver gets written in Rust it'll become mandatory. So either the Rust integration will fail and nothing important will get written in it, or it won't be optional. I'm not sure what comfort that's supposed to bring.

One is a Rust frontend to GCC (https://github.com/Rust-GCC/gccrs) while the other is a GCC backend to the existing Rust compiler (https://blog.antoyo.xyz/rustc_codegen_gcc-progress-report-12). It might take a while for these to bear fruit, but it’ll be awesome when they do. That should address the very valid concern that the full Linux kernel won’t compile for all supported architectures.

And it’s not really a problem that the GCC effort will take time. The headline of this article implies that the Rust integration is nearly done but it’s only the beginning. Based on the issue tracker there’s years of work left to get everything working perfectly. That’s enough time to get GCC supported well.