error: compilation successful
  --> $DIR/range-2.rs:13:1
   |
LL | / pub fn main() { #![rustc_error] // rust-lang/rust#49855
LL | |     let r = {
LL | |         let a = 42;
LL | |         let b = 42;
...  |
LL | |     //~| ERROR `b` does not live long enough
LL | | }
   | |_^

error: aborting due to previous error