error[E0373]: closure may outlive the current block, but it borrows `x`, which is owned by the current block
  --> $DIR/unboxed-closure-region.rs:8:9
   |
LL |         || x
   |         ^^ - `x` is borrowed here
   |         |
   |         may outlive borrowed value `x`
   |
note: block requires argument type to outlive `'1`
  --> $DIR/unboxed-closure-region.rs:6:9
   |
LL |     let _f = {
   |         ^^
help: to force the closure to take ownership of `x` (and any other referenced variables), use the `move` keyword
   |
LL |         move || x
   |         ++++

error: aborting due to previous error

For more information about this error, try `rustc --explain E0373`.