Homebrew not recognizing rustup toolchains

How to make aware Homebrew that toolchains already exist and available through rustup?
Setting ~/.rustup//bin in PATH will affect rustup toolchain updates and other defaults set by rustup?

Here is an example : brew info click

I don't have brew installed rust. Vs. This related question

Thank you and a wonderful 2020 ahead to all.

There may be some kind of empty package replacement you can use to trick it.

AFAIK Homebrew intentionally doesn't cooperate with non-Homebrew Rust, so there's no solution, and there won't be a solution from Homebrew's side.

If you install prebuilt Homebrew packages for stable macOS versions, they won't need to be built, so they won't need Homebrew Rust.

Otherwise, just don't use Homebrew for them. Use cargo install or some other method.