help for E0423 shows unhelpful expanded macro

Code

struct Foo{
    attr: (),
}

fn main() {
    Foo(vec![1]);
}

Current output

error[E0423]: expected function, tuple struct or tuple variant, found struct `Foo`
  --> src/main.rs:6:5
   |
 1 | / struct Foo{
 2 | |     attr: (),
 3 | | }
   | |_- `Foo` defined here
...
 6 |       Foo(vec![1]);
   |       ^^^^^^^^^^^^
   |
help: use struct literal syntax instead of calling
  --> /playground/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/alloc/src/macros.rs:50:9
   |
50 ~         {
51 ~         attr: <[_]>::into_vec(
52 |             // Using the intrinsic produces a dramatic improvement in stack usage for
53 |             // unoptimized programs using this code path to construct large Vecs.
54 |             $crate::boxed::box_new([$($x),+])
55 ~         )}
   |

Desired output

error[E0423]: expected function, tuple struct or tuple variant, found struct `Foo`
  --> src/main.rs:6:5
   |
 1 | / struct Foo{
 2 | |     attr: (),
 3 | | }
   | |_- `Foo` defined here
...
 6 |       Foo(vec![1]);
   |       ^^^^^^^^^^^^
   |
help: use struct literal syntax instead of calling
   |
   |
 6 -     Foo(vec![1]);
 6 +     Foo{attr: vec![1]};
   |
   |

Rationale and extra context

The expansion of vec! is irrelevant here. Also, the suggestion to change lines 50, 51 and 56 in alloc/src/macros.rs is wrong.

Other cases

The good output is shown when vec![1] is replaced with 1.

Rust Version

1.93.0-nightly 2025-11-25 80d8f292d82d735f8341
Stable: 1.91.1

Anything else?

No response

Start by reproducing the E0423 example from the issue with the vec![1] argument and compare its diagnostic with the scalar-argument case. Trace the compiler's handling of the struct-literal suggestion and the expanded alloc/src/macros.rs span; done means the suggestion points to the source call and shows the desired Foo{attr: vec![1]} replacement without macro internals.