### Bug description

Consider this external file named `mermaid1.mer`:

```
flowchart LR
  A
```

When running `Quarto` 1.3.55 on the following script I get `Syntax error in graph, mermaid version 9.1.1`:

````
---
title: "Test"
format:
  html:
    self-contained: true
---

```{mermaid}
%%| file: mermaid1.mer
```
````

I'm running Ubuntu 22.

### Checklist

- [X] Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
- [X] Please [format your issue](https://quarto.org/bug-reports.html#formatting-make-githubs-markdown-work-for-us) so it is easier for us to read the bug report.
- [X] Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
- [X] Please document the operating system you're running. If on Linux, please provide the specific distribution.
cscheid
2022-12-13T22:53:23Z
harrelfe
bug mermaid
v1.3
closed
Inputting an external mermaid file throws a syntax error
https://github.com/quarto-dev/quarto-cli/issues/3665