fn main() {
    println!("{:?}", A { a: () });
    println!("{:?}", B { b: () }.b)
}

#[derive(Debug)]
struct A {
    a: (),
}

#[derive(Debug)]
struct B {
    b: (),
}

(Playground)

Output:

A { a: () }
()

Errors:

   Compiling playground v0.0.1 (/playground)
warning: field `a` is never read
 --> src/main.rs:8:5
  |
7 | struct A {
  |        - field in this struct
8 |     a: (),
  |     ^
  |
  = note: `A` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
  = note: `#[warn(dead_code)]` on by default

warning: `playground` (bin "playground") generated 1 warning
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.29s
     Running `target/debug/playground`

I have #[derive(Debug, Deserialize)] struct which is only used as debug print. Since its field is only being used in bail! and println!, the compiler warns about the field being not used.
Is this intended behavior? Should I just add #[expect(dead_code)] for these kind of fields that are only used for logging purpose?

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