4 #[target_feature(enable = "")]
5 //~^ ERROR: attribute should be applied to a function
6 //~| ERROR: feature named `` is not valid
7 //~| NOTE: `` is not valid for this target
9 //~^ ERROR: `#[track_caller]` on closures is currently unstable
10 //~| NOTE: see issue #87417
12 //~^ NOTE: not a function