Document and maintain Python pre-releases

[willingc]

Hi team 👋

I suspect that some maintainers would appreciate an easily installable version of Python pre-releases to demonstrate how their project works with a prerelease's new feature.

As I understand the process of creating a pre-release so far:

• Prereleases are found in named branches on the python-feedstock repo
• The recipe's meta.yaml contains configuration for the release version number and a label to indicate it is a pre-release.

I'm not clear on:

• the series of patches in the meta.yaml file
• how to render/rerender a pre-release branch so the label applies (does it do it automagically with the existing commands?)

If folks see value in this, I would be happy to iterate the details here and then document it. Thanks!

[mingwandroid]

Hey Carol. Apologies for the silence around here! I'll respond in full a bit later.

[willingc]

No worries @mingwandroid. Thanks for looking at it.

[mingwandroid]

I actually wrote a big reply, with some steps to rebase patches but upon trying them they're not working at present so I well, deleted it all!

I will try to get back to you and hopefully we can get 3.8 previews ready before 3.8 is released (ten odd days, right? - and if not let's make a promise to do better for 3.9).

[jjhelmus]

conda-forge/conda-forge.github.io#861 is a request for documentation on setting up pre/dev releases in conda-forge in general which would be beneficial here.

[megies]

3.8.0rc1 is out, would be fantastic to get it built on conda-forge so projects can add it to their CI matrices

[ocefpaf]

Python 3.9 is in alpha at the moment and we need to decide on a policy for our dev releases.

Due to the huge number of patches and the difficult to build python I don't think it is feasible for the maintainers of the feedstock to do all the dev releases (alpha, beta, and RCs). Maybe we should do just the RCs? After all conda-forge is a platform for users and one could argue that only RCs are really meant for user consumption. What do you think @willingc? Also we would not rebuild all of conda-forge for the latest RC, just the basic setuptools/pip stack so users can install stuff in an RCs env.

Pinging @CJ-Wright who brought this in our core meeting recently.

[megies]

Maybe we should do just the RCs? After all conda-forge is a platform for users and one could argue that only RCs are really meant for user consumption

Sounds very reasonable to me 👍