error[E0658]: compiler plugins are experimental and possibly buggy (see issue #29597) --> $DIR/conf_unknown_key.rs:4:1 | 4 | #![plugin(clippy(conf_file="../auxiliary/conf_unknown_key.toml"))] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = help: add #![feature(plugin)] to the crate attributes to enable error: aborting due to previous error For more information about this error, try `rustc --explain E0658`.