error: cannot find derive macro `Sync` in this scope --> $DIR/issue-33571.rs:2:10 | LL | Sync, | ^^^^ | note: unsafe traits like `Sync` should be implemented explicitly --> $DIR/issue-33571.rs:2:10 | LL | Sync, | ^^^^ error: cannot find derive macro `Sync` in this scope --> $DIR/issue-33571.rs:2:10 | LL | Sync, | ^^^^ | note: unsafe traits like `Sync` should be implemented explicitly --> $DIR/issue-33571.rs:2:10 | LL | Sync, | ^^^^ error: aborting due to 2 previous errors