Suggestion for pub(crate) doesn't handle reexports well

[alexcrichton]

First reported upstream this code:

#![warn(unreachable_pub)]

pub use self::m::f;

mod m {
    pub use self::imp::f;  // Recommends pub(crate), but that causes an error above.
    mod imp {
        pub fn f() {}
    }
}

gives the warning:

warning: unreachable `pub` item
 --> src/lib.rs:6:5
  |
6 |     pub use self::imp::f;  // Recommends pub(crate), but that causes an error above.
  |     ---^^^^^^^^^^^^^^^^^^
  |     |
  |     help: consider restricting its visibility: `pub(crate)`
  |
note: lint level defined here
 --> src/lib.rs:1:9
  |
1 | #![warn(unreachable_pub)]
  |         ^^^^^^^^^^^^^^^
  = help: or consider exporting it for use by other crates

    Finished dev [unoptimized + debuginfo] target(s) in 0.57s

but the suggestions, when applied, doesn't compile!

[estebank]

Should it suggest pub mod m instead?

[ehuss]

Should it suggest pub mod m instead?

Wouldn't that be a change in semantics (m would be reachable by other users)? The original code looks correct to me. The use self::imp::f; item is reachable from the root re-export. It seems to me that the lint shouldn't fire in this case.