unused_extern_crates: does not handle renamed crates used in other modules

[ehuss]

The following suggests removing the extern crate which results in broken code.

#![warn(unused_extern_crates)]

extern crate time as time_crate;

pub mod m {
    pub use time_crate::Duration;
}

The following is also very similar:

#![warn(unused_extern_crates)]

extern crate time as time_crate;

pub mod m {
    use time_crate::Duration;
    pub fn f() {
        Duration::days(1);
    }
}

[petrochenkov]

Fixed in #57557

[ehuss]

@petrochenkov The unused_extern_crates suggestion still doesn't seem to be working right in this scenario. Maybe this should stay open? Now, instead of suggesting removing the extern crate, it suggests replacing it with use, but that still does not compile.

#![warn(unused_extern_crates)]

use time as time_crate;

pub mod m {
    pub use time_crate::Duration;  // Error, time_crate not found.
}

[petrochenkov]

@ehuss
Could you open a new issue?
"Replace extern crate with use" is actually an entirely different thing from "extern crate is unused", I don't know why they merged it into the same lint.

[ehuss]

Ok, filed #57672. Thanks for taking a look and all the fixes!