### Bug description

The code below fails to render with the following error on Quarto v0.9.600:

```
ERROR: TypeError: item.author.join is not a function
```

````
---
format: html
listing: 
  - id: table
    type: table
    contents:
      title: "My cool report"
      subtitle: "It has neat things in it"
      date: "2022-06-23"
      author: "Tom Mock"
---

::: {#table}
:::

````

If I remove the `author: name` key-value pair the rest of the document will render successfully.
![Screen Shot 2022-06-23 at 9 57 09 AM](https://user-images.githubusercontent.com/29187501/175329899-6fb93357-75c5-436f-b2e3-4d59561cc710.png)



### Checklist

- [X] [formatted your issue](https://yihui.org/issue/#please-format-your-issue-correctly) so it is easier for us to read?
- [X] included a minimal, self-contained, and reproducible example?
- [X] documented the quarto version you're running, by providing the output produced by `quarto check` in a terminal in your issue?
- [ ] documented the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
- [ ] documented which operating system you're running? If on Linux, please provide the specific distribution as well.
- [X] upgraded to the latest version, including your versions of R, the RStudio IDE, and relevant R packages?
dragonstyle
2022-06-23T14:57:41Z
jthomasmock
bug
1.0
closed
Manually generating listing with author results in error.
https://github.com/quarto-dev/quarto-cli/issues/1205