error[E0596]: cannot borrow `*inner` as mutable, as it is behind a `&` reference --> $DIR/issue-91206.rs:13:5 | LL | inner.clear(); | ^^^^^ `inner` is a `&` reference, so the data it refers to cannot be borrowed as mutable | help: consider specifying this binding's type | LL | let inner: &mut Vec = client.get_inner_ref(); | +++++++++++++++++ error: aborting due to previous error For more information about this error, try `rustc --explain E0596`.