Main issue is drivers. One of the best places to take advantage of rust’s memory safety is in hardware drivers, and those would be hard to share between separate kernels.

That entire talk, and the complaint that Ts’o responded to was that to continue with rust, there needs to be some responsibility from the guys working on the underlying C bindings to not break downstream dependencies if they refactor code.

The answer from some of the Kernel developers, and vocally by Ts’o was: lol no fuck you and your toy language.