|  | warning: unexpected `cfg` condition value: `foo` | 
|  | --> $DIR/empty-values.rs:7:7 | 
|  | | | 
|  | LL | #[cfg(foo = "foo")] | 
|  | |       ^^^^^^^^^^^ help: remove the condition | 
|  | | | 
|  | = note: no expected values for `foo` | 
|  | = help: to expect this configuration use `--check-cfg=cfg(foo, values("foo"))` | 
|  | = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration | 
|  | = note: `#[warn(unexpected_cfgs)]` on by default | 
|  |  | 
|  | warning: unexpected `cfg` condition value: (none) | 
|  | --> $DIR/empty-values.rs:11:7 | 
|  | | | 
|  | LL | #[cfg(foo)] | 
|  | |       ^^^ help: remove the condition | 
|  | | | 
|  | = note: no expected values for `foo` | 
|  | = help: to expect this configuration use `--check-cfg=cfg(foo)` | 
|  | = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration | 
|  |  | 
|  | warning: 2 warnings emitted | 
|  |  |