src/test/ui/issues/issue-49824.stderr

   1 error: captured variable cannot escape `FnMut` closure body
   2   --> $DIR/issue-49824.rs:4:9
   3    |
   4 LL |       let mut x = 0;
   5    |           ----- variable defined here
   6 LL |       || {
   7    |        - inferred to be a `FnMut` closure
   8 LL | /         || {
   9 LL | |
  10 LL | |             let _y = &mut x;
  11    | |                           - variable captured here
  12 LL | |         }
  13    | |_________^ returns a closure that contains a reference to a captured variable, which then escapes the closure body
  14    |
  15    = note: `FnMut` closures only have access to their captured variables while they are executing...
  16    = note: ...therefore, they cannot allow references to captured variables to escape
  17
  18 error: aborting due to previous error
  19