Welcome to a large pile of hacks masquerading as a PoC. This repository proves that it's possible to write a Terraform Provider in Rust, but does not say it's a good idea. The official docs basically say "write all providers in Go" and that's definitely the easiest and most supported path. This merely proves other options do in fact work.
https://tevps.net/blog/2021/11/7/poc-terraform-provider-rust/ has more information about this.
