1 error: unused extern crate
2 --> $DIR/extern-crate-used.rs:18:1
4 LL | extern crate core;
5 | ^^^^^^^^^^^^^^^^^^ help: remove it
7 note: the lint level is defined here
8 --> $DIR/extern-crate-used.rs:6:9
10 LL | #![deny(unused_extern_crates)]
11 | ^^^^^^^^^^^^^^^^^^^^
13 error: aborting due to previous error