#[derive(Arbitrary)] causes a clippy warning

[KeenS]

Running clippy against this code generates following warning

use proptest_derive::Arbitrary;

#[derive(Debug, Arbitrary)]
struct User {
    id: i32,
}

fn main() {}

$ cargo clippy -- -Wclippy::all
    Checking proptest-clippy v0.1.0 (/home/shun/Rust/proptest-clippy)
warning: passing a unit value to a function
 --> src/main.rs:5:5
  |
5 |     id: i32,
  |     ^^
  |
  = note: `-W clippy::unit-arg` implied by `-W clippy::all`
  = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unit_arg
help: move the expression in front of the call and replace it with the unit literal `()`
  |
5 |     {
6 |         Arbitrary;
7 |         id
8 |     }: i32,
  |

warning: 1 warning emitted

    Finished dev [unoptimized + debuginfo] target(s) in 0.04s

This is too noisy. Is there any chance to address this issue in the library side?

Note that adding #[allow(clippy::unit_arg)] to the type doesn't solve this problem because the warning is from the generated code. One (cumbersome) way to silence this warning in user side is wrapping the definition with mod and allow all lints inside the mod:

mod types {
    #![allow(clippy::all)]

    use super::*;
    #[derive(Debug, Arbitrary)]
    pub(super) struct User {
        pub(super) id: i32,
    }
}

Though the warning can be silenced by the method above, it would be grateful if the derive macro generates that code.

[ghost]

A Clippy bug has already been logged for this. rust-lang/rust-clippy#6594

Personally, I wouldn't add work arounds for Clippy bugs.

[KeenS]

Then I'll watch that issue. Thank you.