Rustup version and updating

I just ran "rustup update" and it all seemed to go well until the very end, where I have these lines:
stable-aarch64-apple-darwin unchanged - rustc 1.69.0 (84c898d65 2023-04-16)
stable-x86_64-apple-darwin update failed - rustc 1.50.0 (cb75ad5db 2021-02-1

The disturbing thing is that I'm on an Apple Silicon (M2) Mac. What should I do about this? I'm not above erasing all traces of Rust and starting clean, if that's what it takes.)

since you are on Apple silicon, the x86_64 host toolchain is useless anyway, just uninstall it, I wonder how it get installed in the first place? if you need to build for x86_64 platform, you can simply add an x86_64 target and use cross compiling.

Whhat might be the incantation to do that? Understand that everything seems to work properly. "rustc --version" reports

rustc 1.69.0 (84c898d65 2023-04-16).

As to how things ""got that way", IIRC, I did "brew install rust" before I read about rustup.. That's why I wonder if a flurry of well-directed "rm -rf"'s foolowed by installing rustup as documented might be my best strategy.

Did you do "brew uninstall rust"?

Brew is great for many things - but don't know why rust is there...

I turns out I did not "recall correctly". At least "brew list" did not report the presence of rust."