error[E0742]: visibilities can only be restricted to ancestor modules --> $DIR/relative-2018.rs:7:12 | LL | pub(in ::core) struct S4; | ^^^^^^ error: relative paths are not supported in visibilities in 2018 edition or later --> $DIR/relative-2018.rs:9:12 | LL | pub(in a::b) struct S5; | ^--- | | | help: try: `crate::a::b` error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0742`.