I understand that these replacements written in Rust for the base system 
utilities may have additional functionality that may be useful, but how 
far are we going to go with this? Do you intend to replace the entire 
OpenBSD userspace with these new tools written in Rust? If this is the 
case, and what you want is an imitation of UNIX written in Rust, you 
could use Redox OS [1], I think you will be happier with it than with 
OpenBSD.

[1]: https://redox-os.org