False positive for `new_without_default_derive`

[sgrif]

Given the following code:

use std::collections::HashMap;

#[derive(Default)]
#[allow(missing_debug_implementations)] // Can't derive debug
pub struct Registry<Env> {
    job_types: HashMap<&'static str, Env>,
}

impl<Env> Registry<Env> {
    pub fn new() -> Self {
        Registry {
            job_types: Default::default(),
        }
    }
}

Clippy will suggest adding #[derive(Default)] on a struct that already has it.

Rust 1.31.1
clippy 0.0.212 (2e26fdc 2018-11-22)

I can't reproduce this error on the playground.
The playground's current version 0.0.212 (2018-12-30 39bd844).
Playground

[flip1995]

Maybe this was fixed in #3558.