relibc VS windows-kernel-rs

That is what Go does. BSDs hate it. https://github.com/redox-os/relibc could be repurposed for this easily enough.

A C standard library rewritten in Rust already exists. [0]

glibc has its share of CVEs, and many of the bugs are of the double free, use-after-free, buffer overflow variety. [1]

[0]: https://github.com/redox-os/relibc

It is entirely possible to write a libc replacement in Rust. In fact, Redox has done so. There is nothing preventing that library from providing a POSIX interface both to C programs and to the Rust libc FFI crate.

This is more a Rust question than a Zig question. In Rust, the choice of a specific libc (or to not use a libc) is part of the "target", for example many hardware platforms have gnu/musl/none targets. See also relibc or mustang for pure-rust alternatives. Each libc alternative require some work to integrate into Rust.

There have been a few attempts to replace libc, at least on Linux - for example Rustix, and Relibc.

There is in fact already a library that does that https://github.com/redox-os/relibc

There's relibc.

I haven't tried them out myself, but https://github.com/StephanvanSchaik/windows-kernel-rs exists. Has a bunch of code, though it hasn't been updated in a long time, so it may have bitrotted.

I recently read the original article from 2020, and kept thinking to myself how surely this is all easier by now. So this update is very welcome. windows-kernel-rs looks especially promising as a starting point, with a tutorial to get you started