### Discussed in https://github.com/quarto-dev/quarto-cli/discussions/2678

<div type='discussions-op-text'>

<sup>Originally posted by **cbrnr** September 30, 2022</sup>
Recently, it took me longer than I'd like to admit to find out why the following code chunk gets evaluated despite setting the corresponding option:

````
---
title: Test
---

```{r}
#| eval: false
cat("Hello")
```
````

If you want to reproduce, copy this example to a file `test.qmd` and preview it with `quarto preview test.qmd`.

In fact, the cell is evaluated because I accidentally used a non-breaking space (U+00A0, <kbd>⌥</kbd><kbd>Space</kbd> on a Mac) instead of a normal space after the `#|` characters. I now turned on `"editor.unicodeHighlight.includeComments": true` and `"editor.unicodeHighlight.nonBasicASCII": true` in Visual Studio Code, which makes this obvious, but I thought that maybe Quarto could issue a warning (or info) when encountering unknown chunk options. Currently, I didn't find anything even after setting `--log-level info`. WDYT?</div>
cscheid
2022-09-30T08:21:53Z
cderv
bug yaml-validation
v1.2
closed
chunk options with non-breaking space does not work and are not shown as invalid
https://github.com/quarto-dev/quarto-cli/issues/2681