error: Unexpected input port: . Expected one of: `0`, `1` --> tests/compile-fail/surface_port_join.rs:6:42 | 6 | source_iter([(1, 1), (2, 2)]) -> j; | ^ error: Unexpected input port: . Expected one of: `0`, `1` --> tests/compile-fail/surface_port_join.rs:7:42 | 7 | source_iter([(3, 3), (4, 4)]) -> j; | ^ error: Missing expected input port(s): `0`, `1`. --> tests/compile-fail/surface_port_join.rs:5:13 | 5 | j = join() -> for_each(std::mem::drop); | ^^^^^^