error[E0711]: feature `foo` is declared stable since 1.29.0, but was previously declared stable since 1.0.0
  --> $DIR/E0711.rs:10:1
   |
LL | #[stable(feature = "foo", since = "1.29.0")]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0711]: feature `foo` is declared unstable, but was previously declared stable
  --> $DIR/E0711.rs:14:1
   |
LL | #[unstable(feature = "foo", issue = "none")]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0711`.