1error[E0596]: cannot borrow `bar` as mutable, as it is not declared as mutable 2 --> $DIR/issue-81700-mut-borrow.rs:3:5 3 | 4LL | let bar = || { foo(x); }; 5 | --- - calling `bar` requires mutable binding due to mutable borrow of `x` 6 | | 7 | help: consider changing this to be mutable: `mut bar` 8LL | bar(); 9 | ^^^ cannot borrow as mutable 10 11error: aborting due to previous error 12 13For more information about this error, try `rustc --explain E0596`. 14