Problematic YAML metadata block

[jgm]

The following is not parsed as metadata. Nor is any warning or error emitted.

pandoc -s -t native
---
abstract: |-
   a

       b
...
^D
Pandoc
  Meta { unMeta = fromList [] }
  [ HorizontalRule
  , Para
      [ Str "abstract:" , Space , Str "|-" , SoftBreak , Str "a" ]
  , CodeBlock ( "" , [] , [] ) "   b"
  , Para [ Str "\8230" ]
  ]

Changing |- to | fixes it. Removing the indentation from b fixes it. My guess is that pandoc can't convert the blocks (with the code block) into inline content as required by |-. Still, it can probably be made to do something more graceful here.