error[E0004]: non-exhaustive patterns: type std::option::Option<i32> is non-empty
  --> $DIR/E0004-2.rs:14:11
   |
14 |     match x { } //~ ERROR E0004
   |           ^
   |
help: Please ensure that all possible cases are being handled; possibly adding wildcards or more match arms.
  --> $DIR/E0004-2.rs:14:11
   |
14 |     match x { } //~ ERROR E0004
   |           ^

error: aborting due to previous error

If you want more information on this error, try using "rustc --explain E0004"