FP unused_import when the import is only used in rustdoc links

[jendrikw]

I tried this code:

//! This is a link: [`Add::add`].
use std::ops::Add;

I expected to see this happen: No warning

Instead, this happened:

warning: unused import: `std::ops::Add

This is especially annoying when you deny some lints:

cargo build errors, but cargo doc is fine:

#![deny(unused_imports)]
#![deny(rustdoc::broken_intra_doc_links)]
//! This is a link: [`Add::add`].
use std::ops::Add;

When you comment out the use statement, cargo build is fine, but cargo doc errors.

#![deny(unused_imports)]
#![deny(rustdoc::broken_intra_doc_links)]
//! This is a link: [`Add::add`].
//use std::ops::Add;

I know I can use the links syntax with an explicit target, but I prefer the short form for less noise when reading the code.

rustc --version --verbose:

rustc 1.57.0 (f1edd0429 2021-11-29)
binary: rustc
commit-hash: f1edd0429582dd29cccacaf50fd134b05593bd9c
commit-date: 2021-11-29
host: x86_64-unknown-linux-gnu
release: 1.57.0
LLVM version: 13.0.0

[jendrikw]

Oops, dupe of #79542.