The first half of the 6.6 merge window

> Doesn't that increase the difficulty of using newer kernel on older distribution? I feel there is a difference between difficulty of backporting a new kernel and backporting a new kernel and all the required rust machinery, since the version my distro has can no longer build the current kernel.

Distributions can ignore Rust for the time being if they wish to do so. Some distributions, when I checked with them, told me they would be happy to provide a package (or support in some other way) to compile the kernel with the latest Rust release, assuming they need it.

Ubuntu, for instance, offers experimental support for it, by providing a package with the required Rust toolchain.

> In the same vein, I am sure gcc has nice features people would like to use in at least some versions between 5.1 (minimal requirement) and 13.2 (current version).
>
> I am unsure why there is (or will be) difference in policy between those two compilers.

There is definitely a difference nowadays; however, the plan is to remove that difference as soon as it is possible/reasonable. Please see this section in the webpage: https://rust-for-linux.com/rust-version-policy#after-a-minimum-version-is-declared.