error[E0531]: cannot find unit struct/variant or constant `extern` in this scope
  --> $DIR/keyword-extern-as-identifier.rs:14:9
   |
LL |     let extern = 0; //~ ERROR cannot find unit struct/variant or constant `extern` in this scope
   |         ^^^^^^ not found in this scope

error: aborting due to previous error

For more information about this error, try `rustc --explain E0531`.