Allow to ignore .gitignore when watching -- bug with .gitignore in parent folder?

[mlange-42]

I have a project where source for mdBook are generated via Literate Programming (using Yarner).

As mdBook sources are an intermediate artifact, I want to have them ignores by Git. However, if they are listed in the project's .gitignore, watch and serve ignore changes to these files.

I already tried to re-structure my project to have book.toml in a sub-folder and call mdBook there, but they are still ignored (unless I rename/delete the .gitignore in the parent diretory, or remove the directory from it).
The documentation says that ignore files in parent directories are ignored, so I would expect it to work.

If this is the intended behaviour, it would be good to have a command line option to ignore the .gitignore, or to somehow "force" watching a folder.

Using mdBook 0.4.7