6837.md

```
% pandoc -t markdown --markdown-headings=setext
## Hi

### Ok
^D
Hi
--

### Ok
```

```
% pandoc -t markdown+lhs
# Hi
^D
[WARNING] Rendering heading 'Hi' as a paragraph.
  ATX headings cannot be used in literate Haskell, because '#' is not
  allowed in column 1. Consider using --markdown-headings=setext.
Hi
```

```
% pandoc -t markdown --markdown-headings=atx
Hi
--
^D
## Hi
```