https://github.com/laramies/theHarvester/pull/229/files
laramies/theHarvester#52
if you need an example.

https://www.kali.org/news/kali-default-non-root-user/ this news came up just in time. Hopefully, you can put more effort now

@blshkv We have been working to update the install file and a few other bug fixes. But this is definitely on our list to accomplish soon. Thank you.

@blshkv I am new to the Python ecosystem, so forgive my ignorance, but I am trying to figure out how this would work for an application like Empire which requires quite a few things installed outside of Python to work properly such as Powershell. Do you have any examples of application with a similar problem?

setup.py is used to install python packages only (including python bindings). Non-python packages should be installed separately (using "pkg-manager install powershell"), you can provide a shell script for users' convenience, but that's hard and useless usually as you would have to detect user's OS and call a specific package manager for each distro. The goal should be to create a distro package, so end-user would simply run "pkg-manager install empire".
Also see andresriancho/w3af#17500

@blshkv this project is using poetry, no need for a setup.py file ;)

https://github.com/BC-SECURITY/Empire/blob/master/pyproject.toml

Thanks, I noticed. However, it does not install anything. I'm not an expert here, but it may be that the [tool.poetry.scripts] and include= sections are missing. Here is a similar working pyproject if you want to compare:
https://github.com/byt3bl33d3r/DeathStar/blob/master/pyproject.toml

EDIT: also, a system-wide installation (the tool is installed via package manager and run as a regular user) is still not supported