Bug in axe accessibility checks for revealjs

[paytonej]

Description

Quarto >1.8 has integrated support for axe-core accessibility checking html. The docs say that the axe YAML metadata configuration can be added to HTML formats (html, dashboard, and revealjs).

However, adding axe to the yaml for the revealjs format results in an error in compiling the sass themes. The error is:

ERROR: Theme file compilation failed:

Error: Undefined variable.
   ╷
67 │   border: 1px solid $body-color;

Line 67 defining the border is in quarto.js This suggests that theme file sass compilation is occurring after quarto.js inclusion, though it needs to happen before.

Accessibility enhancements should be high-priority due to new rules taking effect in April 2026 under Title II of the Americans with Disabilities Act and the requirements of the European Accessibility Act (EAA), which went into effect in June 2025. Many users are now liable for the documents they render meeting these requirements.

Related discussion items:

• Ensure Quarto Meets WCAG 2.1 AA Standards #12644
• Increase options/guidance for compliance with Web Content Accessibility Guidelines (WCAG) in revealjs HTML output #8621
• https://github.com/orgs/quarto-dev/discussions/11847

Minimal (not) working example attached.
axe-error-min-example.md

[mcanouil]

Thanks for the report.
Although, why did you open a bug as a feature request discussion? Would you mind opening an issue and filling it with plain text as demonstrated?

Also note that you can share plain document without attaching them which requires user to download the file to see it, which is not very much accessible as opposed to plain text following the guidelines on issues and discussions templates.

[paytonej]

How do I open a bug discussion? When starting a new discussion I only see three options: "Feature Requests", "Q&A", and "Show & Tell". If reporting a bug was a discussion option, I would have chosen that.

Thanks for the suggestion for sharing a plain document -- however, do you mean putting the document in-line? It is not possible to upload a *.qmd, as it is not one of the supported file formats.

[mcanouil]

Discussions are for discussions, supports, and questions as highlighted in the menu and the templates.
The formatting guidelines are also provided in the appropriate templates such as Q&A https://github.com/orgs/quarto-dev/discussions/new?category=q-a and issues.

Bug reports are "issues" which are mentioned/linked in all templates.
Issues can be found on any repository and in this case Quarto CLI: https://github.com/quarto-dev/quarto-cli/issues

• https://github.com/quarto-dev/quarto-cli/issues/new?template=bug_report.yml

[paytonej]

For what it's worth, the link for "issues" only appears on the individual repositories and not when visiting https://github.com/quarto-dev. It's a little confusing. I'll open up an issue and reference this discussion post.