PDF export seems broken TypeError: _a7.forEach and mdast

[mfouesneau]

I'm unsure what is happening; it seems there is an issue with the PDF export (only).

• myst v1.6.1
• python 3.13

Description

I have some notebooks that I would like to export as PDFs. The HTML export works fine.

 myst build --execute --pdf
📬 Performing exports:
   review.ipynb -> _build/exports/index.pdf
⛔️ review.ipynb Error reading file: TypeError: _a7.forEach is not a function
⛔️ review.ipynb Expected mdast to be processed
⛔️ review.ipynb Expected mdast to be processed
Error: Could not load file information for review.ipynb

I assume that the TypeError is the main issue, but I have no idea what is going on.

Note: --pdf, --tex, --typst generate the same error