ERROR: "No inspectable targets"-error when rendering PDF containing Mermaid diagram

[streepvaren]

Bug description

Hello,

Í'm using:

• Latest version of R (4.2.2)
• Latest version of Rstudio (2022.12.0 Build 353)
• Latest Quarto (version 1.2.335)
• Windows 10 Enterprise 22H2

When rendering a PDF from a .QMD-file containing a Mermaid diagram (https://quarto.org/docs/authoring/diagrams.html), my Rstudio gives the error "ERROR: No inspectable targets" and crashes (I'm unable to press stop).
In the past the same .QMD file rendered to PDF without any problem. Rendering to .HTML still works. The same error was recently reported by an Obsidian user: https://forum.obsidian.md/t/about-quarto-no-inspectable-targets-error/54757.

The .QMD-file i'm using can be found in the attached .ZIP (Github doesn't allow uploading QMD's directly, therefore I zipped).

Thanks for the good work!

Best,
Thomas

testdia.zip

Checklist

• 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.
• Please format your issue so it is easier for us to read the bug report.
• Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
• Please document the operating system you're running. If on Linux, please provide the specific distribution.

[cscheid]

Can you try with our 1.3 prereleases? I'm not on windows, but I can't reproduce the issue:

[streepvaren]

Dear Carlos,

After installing the 1.3.247 prerelease I still get the error when rendering a PDF (HTML works fine).

This time the error is more complex:

ERROR: No inspectable targets

Error: No inspectable targets
    at defaultTarget (file:///C:/Users/20003963/AppData/Local/Programs/Quarto/bin/quarto.js:55313:23)
    at Chrome._fetchDebuggerURL (file:///C:/Users/20003963/AppData/Local/Programs/Quarto/bin/quarto.js:55436:37)
    at async Chrome._start (file:///C:/Users/20003963/AppData/Local/Programs/Quarto/bin/quarto.js:55392:25)

I'm using the latest version of Google Chrome (110.0.5481.178 (Official build) (64-bits))

Best regards,
Thomas

[cscheid]

@cderv will know the details, but there are issues with Windows and headless Chrome.

[cderv]

I can reproduce with using Chrome browser from my system.

It works ok if I use chromium install with Quarto quarto install tools chromium - something must have changed with newest Chrome browser. I need to look into that.

Doc from the Zip to reproduce

---
title: "TestDiagram"
format: pdf
editor: visual
---

## Quarto


```{mermaid}
flowchart TD
    A[Christmas] -->|Get money| B(Go shopping)
    B --> C{Let me think}
    C -->|One| D[Laptop]
    C -->|Two| E[iPhone]
    C -->|Three| F[fa:fa-car Car]
```

[streepvaren]

Thank you very much for the quick help @cscheid and @cderv! quarto install tools chromium fixed the problem!

Best regards,
Thomas

[cderv]

@cscheid I reopened as I think it should be solves for any Chrome browser. Or do you consider our internal chromium to be the solution and we keep it closed ?

Here are some details on what is happening

We are retrieving the debugger url

quarto-cli/src/core/cri/deno-cri/chrome.js

Line 158 in e72f556

const url = await this._fetchDebuggerURL(options);

For that some targets are looked into , default being using defaultTarget function

quarto-cli/src/core/cri/deno-cri/chrome.js

Line 74 in e72f556

this.target = options.target || defaultTarget;

For the default targets we are calling

quarto-cli/src/core/cri/deno-cri/chrome.js

Lines 210 to 211 in e72f556

	const targets = await devtools.List(options);
	const result = func(targets);

which query json/list endpoint, calling defaultTarget() on it.

I don't know yet why but with the Chrome browser version mentioned above, this will be empty

targets
(0) []

No targets to inspect.

This why code currently throw the error from

quarto-cli/src/core/cri/deno-cri/chrome.js

Lines 59 to 64 in e72f556

	target = target || backup;
	if (target) {
	return target;
	} else {
	throw new Error("No inspectable targets");
	}

Maybe we need to open a target if none exists (devtools.New()). FWIW, testing with chromium from quarto install, the targets to explore was about:blank

$ targets
[
  {
    description: "",
    devtoolsFrontendUrl: "/devtools/inspector.html?ws=localhost:9222/devtools/page/BA596C8DC87F7F55499F46F0EC363E27",
    id: "BA596C8DC87F7F55499F46F0EC363E27",
    title: "about:blank",
    type: "page",
    url: "about:blank",
    webSocketDebuggerUrl: "ws://localhost:9222/devtools/page/BA596C8DC87F7F55499F46F0EC363E27",
  },
]

@cscheid hope it helps you know what can be done. I'll look closer tomorrow about why we get this in Chrome now and maybe try the fix suggested above

and crashes (I'm unable to press stop).

I reproduce this also. We throw the error and then impossible to stop Quarto.