diagnostic::on_unimplemented notes not displayed

[konnorandrews]

Code

#[diagnostic::on_unimplemented(
    message = "my message",
    label = "my label",
    note = "my note",
)]
pub trait ProviderLt {}

pub trait ProviderExt {
    fn request<R>(&self) {
        todo!()
    }
}

impl<T: ?Sized + ProviderLt> ProviderExt for T {}

struct B;


fn main() {
    B.request();
}

Current output

error[E0599]: my message
  --> src/main.rs:20:7
   |
16 | struct B;
   | -------- method `request` not found for this struct because it doesn't satisfy `B: ProviderExt` or `B: ProviderLt`
...
20 |     B.request();
   |       ^^^^^^^ my label
   |
note: trait bound `B: ProviderLt` was not satisfied
  --> src/main.rs:14:18
   |
14 | impl<T: ?Sized + ProviderLt> ProviderExt for T {}
   |                  ^^^^^^^^^^  -----------     -
   |                  |
   |                  unsatisfied trait bound introduced here
note: the trait `ProviderLt` must be implemented
  --> src/main.rs:6:1
   |
6  | pub trait ProviderLt {}
   | ^^^^^^^^^^^^^^^^^^^^
   = help: items from traits can only be used if the trait is implemented and in scope
note: `ProviderExt` defines an item `request`, perhaps you need to implement it
  --> src/main.rs:8:1
   |
8  | pub trait ProviderExt {
   | ^^^^^^^^^^^^^^^^^^^^^

For more information about this error, try `rustc --explain E0599`.

Desired output

"my note" should appear somewhere in the diagnostic.

Rationale and extra context

Note are displayed in other cases, its something to do with the extra notes this one code generates.

Playground link: https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=f17d6d22abfdaa2607c3002779e5aa16

Other cases

No response

Rust Version

rustc 1.81.0 (eeb90cda1 2024-09-04)
binary: rustc
commit-hash: eeb90cda1969383f56a2637cbd3037bdf598841c
commit-date: 2024-09-04
host: x86_64-unknown-linux-gnu
release: 1.81.0
LLVM version: 18.1.7

Anything else?

No response

[FedericoBruzzone]

Hi, this would be my first contribution to the rust compiler. I am really excited to try to contribute.

I think I have already solved the problem, I will open the PR as soon as I can.

The note field was being completely ignored. I think what is in the picture is the output that everyone expects, anyway I am waiting for direct feedback.