error[E0658]: use of unstable library feature 'unstable_test_feature' --> $DIR/lint-output-format.rs:6:1 | LL | extern crate lint_output_format; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable error[E0658]: use of unstable library feature 'unstable_test_feature' --> $DIR/lint-output-format.rs:7:26 | LL | use lint_output_format::{foo, bar}; | ^^^ | = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable error[E0658]: use of unstable library feature 'unstable_test_feature' --> $DIR/lint-output-format.rs:7:31 | LL | use lint_output_format::{foo, bar}; | ^^^ | = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable error[E0658]: use of unstable library feature 'unstable_test_feature' --> $DIR/lint-output-format.rs:12:14 | LL | let _y = bar(); | ^^^ | = help: add `#![feature(unstable_test_feature)]` to the crate attributes to enable error: aborting due to 4 previous errors For more information about this error, try `rustc --explain E0658`.