error[E0603]: crate import `core` is private --> $DIR/extern-crate-visibility.rs:6:10 | LL | use foo::core::cell; | ^^^^ private crate import | note: the crate import `core` is defined here --> $DIR/extern-crate-visibility.rs:2:5 | LL | extern crate core; | ^^^^^^^^^^^^^^^^^^ help: consider importing this module instead | LL | use std::cell; | ~~~~~~~~~ error[E0603]: crate import `core` is private --> $DIR/extern-crate-visibility.rs:9:10 | LL | foo::core::cell::Cell::new(0); | ^^^^ private crate import | note: the crate import `core` is defined here --> $DIR/extern-crate-visibility.rs:2:5 | LL | extern crate core; | ^^^^^^^^^^^^^^^^^^ help: consider importing this struct instead | LL | std::cell::Cell::new(0); | ~~~~~~~~~~~~~~~ error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0603`.