1*bd70d2d1SLoGinerror: Unknown flag: send 2*bd70d2d1SLoGin --> $DIR/unknown-flag.rs:5:18 3*bd70d2d1SLoGin | 4*bd70d2d1SLoGin5 | #[cast_to([sync, send] Greet)] 5*bd70d2d1SLoGin | ^^^^ 6