error: usage of an `unsafe extern` block
  --> $DIR/unsafe-extern-blocks.rs:8:1
   |
LL | / unsafe extern "C" {
LL | |
LL | |     fn bar();
LL | | }
   | |_^
   |
note: the lint level is defined here
  --> $DIR/unsafe-extern-blocks.rs:1:9
   |
LL | #![deny(unsafe_code)]
   |         ^^^^^^^^^^^

error: aborting due to 1 previous error