Failing auto fix for `derivable_impls`

Summary

clippy fails to apply an auto fix correctly for the lint derivable_impls. Here's a link to the file in my repo.

Reproducer

I tried this code:

enum Direction {
    North,
    East,
    South,
    West,
}
use std::collections::HashSet;

use Direction::*;

impl Default for Direction {
    fn default() -> Self {
        Direction::North
    }
}

I expected to see this happen:

The applied auto fix should produce:

#[derive(Default)]
enum Direction {
    #[default]
    North,
    East,
    South,
    West,
}
use std::collections::HashSet;

use Direction::*;

Instead, this happened:

The manual Default implementation was removed, but the derived one was not added:

enum Direction {
    North,
    East,
    South,
    West,
}
use std::collections::HashSet;

use Direction::*;

Version

rustc 1.68.0 (2c8cc3432 2023-03-06)
binary: rustc
commit-hash: 2c8cc343237b8f7d5a3c3703e3a87f2eb2c54a74
commit-date: 2023-03-06
host: x86_64-unknown-linux-gnu
release: 1.68.0
LLVM version: 15.0.6

Additional Labels

• I-suggestion-causes-error

Start by reproducing the derivable_impls lint with the Rust code shown in the issue and inspect the lint's auto-fix behavior. The fix is complete when applying the suggestion both removes the manual Default implementation and adds #[derive(Default)] with the appropriate #[default] variant.