needless_borrow complains when a type alias with reference is used

[hmvp]

Example code:

pub type SomeError: &'static str;

pub enum MyError {
    SomeErrorKind(SomeError),
}

results in

error: this pattern creates a reference to a reference
  --> file.rs:3:15
   |
3  |     SomeErrorKind(SomeError),
   |                   ^^^^^^^^^ help: change this to: `SomeError`
   |

In my case the SomeError type comes from an external library

[oli-obk]

pub type SomeError = &'static str;

pub enum MyError {
    SomeErrorKind(SomeError),
}

fn main() {}

Produces no such error. Maybe there are derives involved?

[hmvp]

You are right it needs a derive:

#![deny(needless_borrow)]

pub type SomeError = &'static str;

#[derive(Debug)]
pub enum MyError {
    SomeErrorKind(SomeError),
}

fn main() {}

So its probally a duplicate of #2740

[phansch]

This will probably be fixed by #3400