error: unused extern crate
  --> $DIR/unnecessary-extern-crate.rs:6:1
   |
LL | extern crate core;
   | ^^^^^^^^^^^^^^^^^^ unused
   |
note: the lint level is defined here
  --> $DIR/unnecessary-extern-crate.rs:3:9
   |
LL | #![deny(unused_extern_crates)]
   |         ^^^^^^^^^^^^^^^^^^^^
help: remove the unused `extern crate`
   |
LL - extern crate core;
   |

error: unused extern crate
  --> $DIR/unnecessary-extern-crate.rs:9:1
   |
LL | extern crate core as x;
   | ^^^^^^^^^^^^^^^^^^^^^^^ unused
   |
help: remove the unused `extern crate`
   |
LL - extern crate core as x;
   |

error: unused extern crate
  --> $DIR/unnecessary-extern-crate.rs:31:5
   |
LL |     extern crate core;
   |     ^^^^^^^^^^^^^^^^^^ unused
   |
help: remove the unused `extern crate`
   |
LL -     extern crate core;
   |

error: unused extern crate
  --> $DIR/unnecessary-extern-crate.rs:35:5
   |
LL |     extern crate core as x;
   |     ^^^^^^^^^^^^^^^^^^^^^^^ unused
   |
help: remove the unused `extern crate`
   |
LL -     extern crate core as x;
   |

error: unused extern crate
  --> $DIR/unnecessary-extern-crate.rs:44:9
   |
LL |         extern crate core;
   |         ^^^^^^^^^^^^^^^^^^ unused
   |
help: remove the unused `extern crate`
   |
LL -         extern crate core;
   |

error: unused extern crate
  --> $DIR/unnecessary-extern-crate.rs:48:9
   |
LL |         extern crate core as x;
   |         ^^^^^^^^^^^^^^^^^^^^^^^ unused
   |
help: remove the unused `extern crate`
   |
LL -         extern crate core as x;
   |

error: aborting due to 6 previous errors