Can't run Rust on a 486.

This is more an issue with the toolchain than anything else though. Other distributions are hitting the same wall, in OpenBSD, for example.

Apparently you can still buy 80486 chips:

https://octopart.com/search?q=80486&currency=USD&specs=0&cat...

previously: https://news.ycombinator.com/item?id=33308369