Here are a couple of options if anyone is curious: https://github.com/johnthagen/min-sized-rust

FWIW, when rebuilding jless with some of the cargo tweaks mentioned here, as well as in https://www.collabora.com/news-and-blog/blog/2020/04/28/redu..., I managed to get the binary size down to 1.75MB. Better, but still huge.

Note that I did not use tweaks which require rust nightly, as I did not feel like installing it.

I'll bet that a good project for a different person who has idly thought "y'know, I'd like an excuse to learn rust..." could be doing that.