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`
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

warning[E0602]: unknown lint: `foo_qux`
   |
   = note: requested on the command line with `--force-warn foo_qux`
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

warning: 3 warnings emitted

For more information about this error, try `rustc --explain E0602`.