warning: the feature `effective_target_features` is incomplete and may not be safe to use and/or cause compiler crashes
  --> $DIR/feature-gate-effective-target-features.rs:3:30
   |
LL | #![cfg_attr(feature, feature(effective_target_features))]
   |                              ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: see issue #143352 <https://github.com/rust-lang/rust/issues/143352> for more information
   = note: `#[warn(incomplete_features)]` on by default

error: `#[target_feature(..)]` cannot be applied to safe trait method
  --> $DIR/feature-gate-effective-target-features.rs:21:5
   |
LL |     #[target_feature(enable = "avx2")]
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot be applied to safe trait method
LL |
LL |     fn foo(&self) {}
   |     ------------- not an `unsafe` function

error[E0053]: method `foo` has an incompatible type for trait
  --> $DIR/feature-gate-effective-target-features.rs:23:5
   |
LL |     fn foo(&self) {}
   |     ^^^^^^^^^^^^^ expected safe fn, found unsafe fn
   |
note: type in trait
  --> $DIR/feature-gate-effective-target-features.rs:7:5
   |
LL |     fn foo(&self);
   |     ^^^^^^^^^^^^^^
   = note: expected signature `fn(&Bar2)`
              found signature `#[target_features] fn(&Bar2)`

error: aborting due to 2 previous errors; 1 warning emitted

For more information about this error, try `rustc --explain E0053`.