Trying to create website through Gitlab CI

[ManuelAndia]

Hi all, I'm pretty new to MyST and continuous integration so I apologise in advance if my wording is a bit imprecise 😊

I tried looking for similar discussions but struggled to find anything related to my issue, hence this post.

I'm trying to deploy a physics course as a Gitlab "pages" website. I already have a few pages which work great locally with MyST (when I run myst build --html --all for instance), including the different export formats (PDF, docx etc.).

On the main md page, I have the following lines in the frontmatter:

exports:
    - format: docx
      output: ./_build/exports/Index.doc
      id: word-docx
    - format: pdf
      output: ./_build/exports/Index.pdf
      id: pdf-doc
    - format: tex
      output: ./_build/exports/Index.zip
      id: tex-zip
downloads:
  - file: Index.md
    title: This page (source)
  - id: word-docx
    title: This page (Word)
  - id: pdf-doc
    title: This page (PDF)
  - id: tex-zip
    title: This page (LaTeX)
  - file: ./Documents/Example_PDF.pdf
    title: Full course in PDF

As I said, locally this does generate the files I require in the _build/exports folder.

I then try to push all of this to my Gitlab repo, and I have a .gitlab-ci.yml file with the following lines:

- myst build --html --all # build HTML and all other exports (PDF, Word etc.)
- mv _build/html/ public/

I end up getting an error that I don't get when I use MyST offline (I'm only pasting the first 2 lines because the rest is a lot of the same):

💾 Saved template to path _build/templates/tex/myst/curvenote
⛔️ Pages/Index.md 'files.0' file does not exist: _build/templates/tex/myst/curvenote/template.tex (at _build/templates/tex/myst/curvenote/template.yml#template)

This results in the PDF and docx documents not being available for download in the page's download options (but for some reason the tex archive is available for download on some pages, not all).

Does anyone have a clue of what could be happening?

Thanks in advance for your help 🙏
Cheers
Manuel