in the Gnus summary buffer I customized the threading appearance:

``` lisp
(setq-default
   gnus-sum-thread-tree-leaf-with-other "├── "
   gnus-sum-thread-tree-single-leaf "└── "
   gnus-sum-thread-tree-vertical "│ ")
```

When I'm reading my mail or mailing lists like emacs-devel via news.gmane.io it works as expected.
Expected behaviour looks something like [this](https://en.wikipedia.org/wiki/Gnus#/media/File:Gnus-reading-news.png) as opposed to the [default behaviour](https://i.ytimg.com/vi/g-gpAALqDW8/maxresdefault.jpg).
Unfortunately I can't get this to work in [nnhackernews](https://gitawonk.com/dickmao/nnhackernews.git) and [nnreddit](https://gitawonk.com/dickmao/nnreddit).
There threads just get indented by whitespace.

Does anyone how what I am missing here?