False positive on the unreachable_pub lint

[alexcrichton]

The following code:

#![crate_type = "lib"]
#![feature(rust_2018_preview)]
#![warn(rust_2018_idioms)]

pub use self::m1::foo;

mod m1 {
    pub use self::m2::foo;


    mod m2 {
        pub fn foo() {}
    }
}

when compiled yields:

warning: unreachable `pub` item
 --> src/lib.rs:8:5
  |
8 |     pub use self::m2::foo;
  |     ---^^^^^^^^^^^^^^^^^^^
  |     |
  |     help: consider restricting its visibility: `crate`
  |
note: lint level defined here
 --> src/lib.rs:3:9
  |
3 | #![warn(rust_2018_idioms)]
  |         ^^^^^^^^^^^^^^^^
  = note: #[warn(unreachable_pub)] implied by #[warn(rust_2018_idioms)]
  = help: or consider exporting it for use by other crates

but the corrected version doesn't compile!

[alexcrichton]

cc @zackmdavis, do you know where this might be coming up?

[zackmdavis]

Duplicate of #47816? I'm pretty busy right now, but might be able to take a look Saturday.

[alexcrichton]

Indeed, thanks! No rush as well :)