`#[expect(..)]` not supported on function arguments

[Jarcho]

This isn't used by many lints, but clippy does have a few. This is the only location I've noticed, but I haven't checked everywhere.

fn f(
    #[expect(clippy::ptr_arg)] _x: &Vec<u32>,
) {}

I expected to see this happen: Nothing

Instead, this happened:

error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters

cc #54503

[xFrednet]

Thank you for the report

@rustbot claim

@rustbot label +F-lint-reasons