Thanks @mcanouil !

To be clear @ThierryO we fixed a similar issue while ago (2d3a5f9) and we may have missed some use case, but we need to know where this URL was provided in Quarto configuration, otherwise we don't know where to look.

We use it in the navbar of a html book. The link provides a link to the relevant line in _quarto.yml. The file is part of a working example of a quarto extension.

It seems exactly same usage as initial problem

• Citeproc warning when using a Mastodon profile link #3493

Would it mean this is a regression 🤔 ?

We need to come up with a simple example to reproduce and add as a test project

I can't reproduce on a website.

Note that the project is far from a default project.
A book cannot have a navbar but here it has one.
My guess is that the issue comes from the extension rather than Quarto itself.

Note that the project is far from a default project.

Yes. This is an extension providing our corporate identity.

A book cannot have a navbar but here it has one.

The documentation says otherwise

Indeed, sorry, I missed that, but now I confirm the issue is not Quarto (I mean it produces the right result, but with [WARNING] Citeproc: citation MickaelCanouil not found warning).

1. quarto create project book
2. _quarto.ml

project:
  type: book

book:
  title: "demo"
  author: "Norah Jones"
  date: "2/25/2025"
  navbar:
    pinned: true
    right:
      - text: Mastodon
        href: https://fosstodon.org/@MickaelCanouil
  chapters:
    - index.qmd
    - intro.qmd
    - summary.qmd
    - references.qmd

bibliography: references.bib

format:
  html:
    theme:
      - cosmo
      - brand
  pdf:
    documentclass: scrreprt

The warning still not appear in website project, so it might be a Book project oversight from the last fix.

I've created a minimal examples without extensions.

_quarto.yml

project:
  type: book

bibliography: references.bib

format:
  html: default

book:
  chapters:
    - index.md
  navbar:
    left:
      - text: Cover
        file: index.md
    right:
      - icon: mastodon
        href: https://mastodon.online/@inbo

index.md

# Abstract {-}

Excerpt on ecology taken from [Wikipedia](https://en.wikipedia.org/wiki/Ecology)

references.bib

@Misc{R-3.0.1,
  Title                    = {{R: A language and environment for statistical computing. Version 3.0.1}},

  Author                   = {{R Core Team}},
  Year                     = {2013},

  Address                  = {Vienna, Austria},
  Publisher                = {R Foundation for Statistical Computing},
  Url                      = {http://www.r-project.org/}
}

Console output of quarto render

pandoc 
  to: html
  output-file: index.html
  standalone: true
  toc: true
  number-sections: false
  section-divs: true
  html-math-method: mathjax
  wrap: none
  default-image-extension: png
  variables: {}
  
metadata
  crossref:
    chapters: true
  document-css: false
  link-citations: true
  date-format: long
  lang: en
  bibliography:
    - references.bib
  
[WARNING] Citeproc: citation inbo not found
Output created: _book/index.html

This still happen in this case because we do pass the book metadata (we do not for website nor for about which previous #3493 was about.

Pandoc parses Metadata string as Mardown, and so it will resolve citation syntax in there unless escaped.

Unfortunately, escaping like

href: https://mastodon.online/\@inbo

does not work either because of #3493 fix as it will escape again

href: https://mastodon.online/\\@inbo

which modify the intent.

So this could be fixed in a scoped manner by also escaping in the pandoc metadata.

Or we could also see why book metadata is not deleted. But I think now it is too late to remove it as users expect meta shortcode to work on book meta.

For reference, this is the intermediate metadata file we pass to pandoc

crossref:
  chapters: true
document-css: false
link-citations: true
quarto-template-params:
  title-block-categories: 'true'
date-format: long
lang: en
fig-responsive: true
quarto-version: 99.9.9
bibliography:
  - references.bib
book:
  chapters:
    - index.md
  navbar:
    left:
      - text: Cover
        file: index.md
      - icon: mastodon
        href: https://mastodon.online/@inbo
    tools: []
  render:
    - type: chapter
      file: index.md
      depth: 0
toc-title: Table of contents

and why @inbo is parsed.

We could try escape, or use pandoc-native too maybe.

A workaround is to replace @inbo with @inbo.

Thanks - this could be a better escape than replacing @ by \@ in our existing process 🤔