Thanks in particular to John’s response, I was able to figure out how to get the json5 requirement into the package metadata.
I also added a legacy setup.py as recommended. I actually think I need that to satisfy a goofy, internal back end we are using.
A lot of my confusion regarding these methods comes from stumbling into the new pattern with a project.toml and everything else when investigating a random setuptools bug that had happened a few months ago. From that correspondence, I had found out about the new paradigm. So when I had to make a new Python package, I decided to look it up in more detail and found the tutorial I was using.
The tutorial was still deferring to setuptools. It’s not that I need or want to use it. I’m trying to figure out what I should be doing to get ahead of the standard changes. So if there are additional steps I should be taking that I’ll want to get that out of the way here too. The situation I’m working on right now is what I’d consider to be a simplified, yet still typical one so it’s a decent place to learn the new conventions.