warning: unused extern crate
  --> $DIR/no-macro-use-attr.rs:6:1
   |
LL | extern crate test_macros;
   | ^^^^^^^^^^^^^^^^^^^^^^^^^ unused
   |
note: the lint level is defined here
  --> $DIR/no-macro-use-attr.rs:4:9
   |
LL | #![warn(unused_extern_crates)]
   |         ^^^^^^^^^^^^^^^^^^^^
help: remove the unused `extern crate`
   |
LL - extern crate test_macros;
   |

warning: 1 warning emitted