Running

./x doc library/core/ --json
./x test ./tests/rustdoc-json/generic_impl.rs # to force a jsondoclint build.
./build/host/stage0-tools-bin/jsondoclint ./build/host/json-doc/core.json

Outputs a large number of errors

• Identify the core issue, find MCVE's, file issues
  • Rustdoc JSON Produces dangling ID's when pub useing #[doc(hidden)] items. #106379
  • rustdoc-json: Dangling ID for trait impl with pub struct in #[doc(hidden)] mod #112852
  • rustdoc-json: Dangling ID when private struct used in bound for pub-on-pub impl #113674
  • more
• Fix issues
  • rustdoc: Strip imports of items which are #[doc(hidden)] #106538
  • Strip impl if not re-exported and is doc(hidden) #113574
  • more
• Run jsondoclint on core.json in CI, so this doesn't regress again.

Originally posted by @aDotInTheVoid in #104064 (comment)