Re: [PATCH 2/6] ci: check formatting of our Rust code

>     I bring this up because, although it hasn't been such a big deal
>     with the existing C code, assuming that developers run `rustfmt`
>     on the code before sending a patch series, then this may become an
>     issue if different developers have `rustfmt` configured to enforce
>     different maximum column width, especially since `rustfmt` is
>     likely to reformat the entire file rather than just the region
>     that has just been edited.  So, if this code gets checked in as-is
>     with these very wide lines, and then someone else, who has
>     `rustfmt` configured for 80-columns edits the file, then it
>     becomes a problem.
>
>     As such, can we also add a project-wide `rustfmt.toml` which, at
>     minimum, sets the maximum line width to 80? For instance:
>
>         max_width = 80
>
> Later in the same thread, I wrote[2]:
>
>     Project guidelines have long suggested 80 columns as a desirable
>     maximum not only for C code, but for pretty much all other
>     resources, including shell code, Perl code, and documentation
>     files. This suggested maximum works well for adherents of
>     80-columns and (presumably) hasn't been too onerous for developers
>     who use wider windows; at least we haven't heard people clamoring
>     to increase the suggested maximum column limit. As such, it does
>     not seem far-fetched to expect that the project guidelines
>     should/could/would also apply to Rust code.
>
> Unfortunately, what little discussion there was petered out quickly
> without resolution, but it seems that it would be a good idea to make
> some sort of decision earlier (while there is still very little Rust
> code committed to the project) rather than later.