error[E0594]: cannot assign to `x`, as it is not declared as mutable
  --> $DIR/cannot-mutate-captured-non-mut-var.rs:9:25
   |
LL |     let x = 1;
   |         - help: consider changing this to be mutable: `mut x`
LL |     to_fn_once(move|| { x = 2; });
   |                         ^^^^^ cannot assign

error[E0596]: cannot borrow `s` as mutable, as it is not declared as mutable
  --> $DIR/cannot-mutate-captured-non-mut-var.rs:13:25
   |
LL |     let s = std::io::stdin();
   |         - help: consider changing this to be mutable: `mut s`
LL |     to_fn_once(move|| { s.read_to_end(&mut Vec::new()); });
   |                         ^ cannot borrow as mutable

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0594, E0596.
For more information about an error, try `rustc --explain E0594`.