(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code UnknownTypeAliasTarget)
  (message "type alias target `Missing` is not a known concrete type")
  (file "<fixture>")
  (span
    (bytes 28 35)
    (range 4 13 4 20)
  )
  (expected "built-in type, known struct, known enum, or known type alias")
  (found "Missing")
  (hint "declare the target type or alias before checking this alias set")
)