There appears to be a lot of variation in how complete the "partially done" commands are. For example od seems fairly complete, but date doesn't even support simple usages like date +%Y%m%d, and sort seems to have a good selection of options, but is missing some relatively important ones like sort keys.

It would be really useful if there were some documentation clarifying how complete t

386 can't use strace

Prerequisite for running on Debian:

$ apt install flex bison libelf-dev libssl-dev bc cpio libncurses5-dev xorriso wget make gawk gcc

Is kmod necessary?

Cargo.toml should probably have the licence in and inclusion in the root.

I think you want this in Cargo.toml:
license = "GPL-2.0-only"

Perhaps the AUTHORS file from busybox as well.

Great work!

Current test code coverage is pretty low (about 13.56%): https://codecov.io/gh/mesalock-linux/mesabox/tree/master

Our target coverage is around 80%.