Has rmarkdown rendering of images included via markdown with alt text changed? How to avoid md markup conversion to html?

[gavinsimpson]

A couple of days ago I noticed that my README.md that is automatically built from the README.Rmd in my repo via GH Actions had changed:

https://github.com/gavinsimpson/gratia/commit/be93b193b8092517d9d75d81e2b565da801efb46

In place of the markdown syntax for images being preserved from the .Rmd source, these are being replaced by HTML with a figure caption. These caption are now being rendered (obviously) inside GitHub and it's annoying.

I had a quick look at Pandoc's recent release notes and didn't see anything related.

I looked at rmarkdown's NEWS.md and saw that there had been a recent release but nothing there seems related to this.

I can't reproduce this behaviour locally but my machine is running an older but supported LTS of Ubuntu and I have an old version of Pandoc (apt reports Version: 2.5-3build2). The version of Pandoc used on GH Actions (on ubuntu-latest) seems to have changed recently: it now reports 3.1.11.

Here's a recent GH Action run: https://github.com/gavinsimpson/gratia/actions/runs/8172627146/job/22343269488#step:7:34

If this is due to a change in Pandoc, are there ways to run the renderer to turn off this feature?