rust-rustfmt-switches from .dir-local.el

[andrewzhurov]

In rust-mode 1.0.6 setting rust-rustfmt-switches in .dir-locals.el has no effect.
E.g., ("--edition" "2024) gets disregarded. (value that's been set globally gets read on save, in my case it was ("--edition" "2018").

It seems possible to configure rust-fmt per-project by setting nil, in which case it reads config from rustfmt.toml, and that's the default now.
Still, may be nice to allow per-project configuration via .dir-locals.el?

[psibi]

(value that's been set globally gets read on save, in my case it was ("--edition" "2018")

Where does it set globally ?

It is intentional that for per project settings, we prefer using rustfmt.toml now. There was a discussion about it in this PR: #571

That being said, if you set rust-rustfmt-switches, rust-mode still respects it and will pass that option. Can you give a small way to reproduce it if that's the case ?