False positive `unused_extern_crates`

[matthiaskrgr]

I tried this code:
(edition 2024)

#![warn(unused_extern_crates)]

#![no_implicit_prelude]
extern crate std;
fn main() {
    let r = 1u16..10;
    std::println!("{:?}", r.is_empty());
}

=>

warning: `extern crate` is not idiomatic in the new edition
 --> src/main.rs:4:1
  |
4 | extern crate std;
  | ^^^^^^^^^^^^^^^^^
  |
note: the lint level is defined here
 --> src/main.rs:1:9
  |
1 | #![warn(unused_extern_crates)]
  |         ^^^^^^^^^^^^^^^^^^^^
help: convert it to a `use`
  |
4 - extern crate std;
4 + use std;

the suggested code

#![warn(unused_extern_crates)]

#![no_implicit_prelude]
use std;
fn main() {
    let r = 1u16..10;
    std::println!("{:?}", r.is_empty());
}

does not compile:

error[E0432]: unresolved import `std`
 --> src/main.rs:4:5
  |
4 | use std;
  |     ^^^ no external crate `std`

For more information about this error, try `rustc --explain E0432`.

[chenyukang]

there is #![no_implicit_prelude], but introduce std with extern crate std;, std::println actually used items in std, so the unused warning message should not be reported.