It would have been helpful if you’d mentioned that the code in question is in themes/theme/layouts/person/list.html. Since the repo doesn’t trigger an error as-is, I had to grep through to find it.
The fundamental problem is that your paginator doesn’t make sense.
Why? Because you’re already in section person, so you don’t need to select all pages of type “person”; Hugo did that for you automatically. Your expression includes the section index page as well as the two single pages, and it didn’t have a valid value for .Params.id, so the index lookup correctly failed. (also, index.md should be _index.md)
By the way, why is there a lightning bolt in the HTML tag? <html ⚡="">
Because this was an AMP page. “Accelerated Mobile Page” and that specification requires that tag. (I removed the other required elements for this GitHub repo to focus on the Hugo issue)
Thank you very much for the tips and the explanation of the context for the range scan of person section pages. I find that understanding the context is one of the biggest challenges when learning Hugo. It never occurred to me that when working on a content section that the context would be that section. I am going to ponder this a bit today and see if I can get full clarity about this.
Thank you also for the great explanation of picking up the index.md page. That makes total sense now.
The lighting bolt is to signal that a page is coded to the AMP specification. I removed all AMP required elements for this repo but I forgot that one!