error: unused extern crate
  --> $DIR/issue-54400-unused-extern-crate-attr-span.rs:12:1
   |
LL | / #[cfg(blandiloquence)]
LL | | extern crate edition_lint_paths;
   | | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-
   | |________________________________|
   |                                  help: remove it
   |
note: the lint level is defined here
  --> $DIR/issue-54400-unused-extern-crate-attr-span.rs:6:9
   |
LL | #![deny(rust_2018_idioms)]
   |         ^^^^^^^^^^^^^^^^
   = note: `#[deny(unused_extern_crates)]` implied by `#[deny(rust_2018_idioms)]`

error: aborting due to previous error