Move from setup.py mostly to pyproject.toml

[mauritsvanrees]

The Zope meta package has a script now to translate setup.py to pyproject.toml. In the end, setup.py will still be there, but only contain from setuptools import setup; setup(). You need to eyeball the results to see if it did not make any mistakes, but apparently it works on all zopefoundation repos. BTW, I did not try it.

I think this would be good for Plone as well.

This can also help as a stepping stone to moving to hatchling or something else, if we ever want that. See discussion in #235 from last year.

This needs some changes in plone.meta: currently you should not manually edit that file, because plone.meta handles everything.

Easiest may be to have a start and end marker in pyproject.toml:

# Generated from:
# https://github.com/plone/meta/tree/main/src/plone/meta/default
# See the inline comments on how to expand/tweak this configuration file
[build-system]
requires = ["setuptools>=68.2,<80", "wheel"]

# START-MARKER-MANUAL-CONFIG
[project]
name = "Products.CMFPlone"
version = "6.2.0.dev0"
...
# END-MARKER-MANUAL-CONFIG

[tool.towncrier]
...

Anything between the start and end marker would be left untouched by plone.meta.

I would want to leave the build-system at the top for clarity, although in the end it does not really matter.

If we want to do this, we probably need our own copy of the script from Zope meta, at least to add the two markers.

[davisagli]

What's the reason for keeping the one-line setup.py? That is probably unnecessary unless we still have some old tooling that tries to run setup.py commands directly.

[mauritsvanrees]

Buildout needs a setup.py for editable installs.

[davisagli]

@mauritsvanrees Shouldn't it use pip install -e so that it can also support build systems other than setuptools?

[mauritsvanrees]

O, it is doing that, but it does not work. Installation seems to work, but Buildout can't find the installed packages afterwards. See some failed tries in buildout/buildout#721

[gforcada]

Yes, I was thinking on that... as my availability is a bit limited as of late, I want to focus on PEP 420 leftovers, and then we can do this move 👍🏾

Or do it on your own without waiting too much on me 😅

[mauritsvanrees]

Buildout needs a setup.py for editable installs.

Sorry, I misremembered. Buildout no longer requires a setup.py. A pyproject.toml is enough. But a non-setuptools build-system still does not work.

So if we make our own version of the Zope script, it should be fine to remove setup.py completely.