warning[E0602]: unknown lint: `foo_qux` | = note: requested on the command line with `--force-warn foo_qux` = note: `#[warn(unknown_lints)]` on by default warning[E0602]: unknown lint: `foo_qux` | = note: requested on the command line with `--force-warn foo_qux` warning[E0602]: unknown lint: `foo_qux` | = note: requested on the command line with `--force-warn foo_qux` warning: 3 warnings emitted For more information about this error, try `rustc --explain E0602`.