error: an `#[unstable]` annotation here has no effect
  --> $DIR/stability-attribute-trait-impl.rs:25:1
   |
LL | #[unstable(feature = "h", issue = "none")]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: `#[deny(ineffective_unstable_trait_impl)]` on by default
   = note: see issue #55436 <https://github.com/rust-lang/rust/issues/55436> for more information

error: module has missing stability attribute
  --> $DIR/stability-attribute-trait-impl.rs:1:1
   |
LL | / #![feature(staged_api)]
LL | |
LL | |
LL | | #[stable(feature = "a", since = "1")]
...  |
LL | |
LL | | fn main() {}
   | |____________^

error: aborting due to 2 previous errors