We would also have to burn a trillion tokens a day verifying all the C code the hard way forever going forward. It would be cheaper to rewrite the kernel in Rust, subsystem and driver by driver at a time.
AI doesn't give a strong guarantee that things work though, while Rust gives a much stronger (not absolute) guarantee.
But maybe the way of the future is to auto-generate proofs that the code is memory safe and then just leave things where they are, instead of doing rewrites that require maintainer buy ins. The advantage of C plus proofs would be that the AI generated proofs could live separately so it wouldn't touch workflows of the maintainers.
The only required output they have to process is evidence of vulnerabilities in changes proposed to them. They could outsource even that to contributors.
Humans manually typing out the bytes of source code has been an outdated method, since around a year. It simply doesn't scale as much as those same humans directing agentic teams. So yes, it would be about prompts.
The hard part isn't the technology for the language transition, that one is present today. pgrust shows the way. It's ensuring maintainers are cooperative, i.e. a social problem. Eventually you diverge too much if you do a fork, so it's better done in cooperation with upstream.
Just check how long it took LLVM or GCC to switch off svn for example, and a language switch is much more involved than a VCS switch.
You mean the pgrust which was recently caught for cheating benchmarks and incapable of even performing basic queries outside the benchmark set? Would love to see pgrust debunked by Jepsen like this other AI-generated, written in Rust, "formally verified" scam.