error[E0658]: #[doc(keyword = "...")] is experimental
  --> $DIR/feature-gate-doc_keyword.rs:1:1
   |
LL | #[doc(keyword = "match")]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/51315
   = help: add #![feature(doc_keyword)] to the crate attributes to enable

error: aborting due to previous error

For more information about this error, try `rustc --explain E0658`.