error: doc alias is duplicated
  --> $DIR/duplicate_doc_alias.rs:4:7
   |
LL | #[doc(alias = "A")]
   |       ----------- first defined here
LL | #[doc(alias = "A")]
   |       ^^^^^^^^^^^
   |
note: the lint level is defined here
  --> $DIR/duplicate_doc_alias.rs:1:9
   |
LL | #![deny(unused_attributes)]
   |         ^^^^^^^^^^^^^^^^^

error: doc alias is duplicated
  --> $DIR/duplicate_doc_alias.rs:6:13
   |
LL | #[doc(alias = "B")]
   |       ----------- first defined here
LL | #[doc(alias("B"))]
   |             ^^^

error: aborting due to 2 previous errors