wrong span for E0277

[jendrikw]

Code

pub fn f() {
    let _: Box<[str]>;
}

Current output

error[E0277]: the size for values of type `str` cannot be known at compilation time
 --> src/lib.rs:2:12
  |
2 |     let _: Box<[str]>;
  |            ^^^^^^^^^^ doesn't have a size known at compile-time
  |
  = help: the trait `Sized` is not implemented for `str`
  = note: slice and array elements must have `Sized` type

Desired output

error[E0277]: the size for values of type `str` cannot be known at compilation time
 --> src/lib.rs:2:12
  |
2 |     let _: Box<[str]>;
  |                 ^^^ doesn't have a size known at compile-time
  |
  = help: the trait `Sized` is not implemented for `str`
  = note: slice and array elements must have `Sized` type

Rationale and extra context

The type that "doesn't have a size known at compile time is "str". The size of a box is known (wither one or two pointers), it is therefore wrong to underline the Box part.

Other cases

Rust Version

1.89.0-nightly (2025-05-17 777d372772aa3b39ba72)

Anything else?

No response

[jendrikw]

@rustbot label D-confusing D-incorrect D-imprecise-spans