Hi, @mrienstra. To keep the submodule up to date in the parent repo, you must make commits to the parent repo to point to the most recent commit in the submodule repo.
There is a Stack Overflow post with more information here:
Your parent repo points to a specific commit in the submodule. That means that this won’t be avoidable:
I’d like to avoid adding a commit to the superproject every time the submodule is updated, to keep the history cleaner.
You must make a new commit in the parent repo to update the submodule. That is just how Git is designed.