Add Python 3.12.0 beta

[hugovk]

Description:

Python 3.12 beta has been released on 22 May 2023 but isn't yet available for GitHub Actions.

The Python release manager asked maintainers to test the beta, so it would be great to be able to test on CI:

We strongly encourage maintainers of third-party Python projects to test with 3.12 during the beta phase and report issues found to [the Python bug tracker (Issues · python/cpython · GitHub) as soon as possible. While the release is planned to be feature complete entering the beta phase, it is possible that features may be modified or, in rare cases, deleted up until the start of the release candidate phase (Monday, 2023-07-31). Our goal is to have no ABI changes after beta 4 and as few code changes as possible after 3.12.0rc1, the first release candidate. To achieve that, it will be extremely important to get as much exposure for 3.12 as possible during the beta phase.

• https://discuss.python.org/t/python-3-12-beta-1-and-feature-freeze-is-here/26982?u=hugovk

Action version:

v4 = v4.6.0

Platform:

• Ubuntu
• macOS
• Windows

Runner type:

• Hosted
• Self-hosted

Tools version:

3.12-dev

https://github.com/actions/python-versions/blob/main/versions-manifest.json

Repro steps:
A description with steps to reproduce the issue. If your have a public example or repo to share, please provide the link.

Set up Python using 3.12-dev:

jobs:
  build:
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
        python-version: [
          "3.12-dev",
        ]
        os: [
          windows-latest,
          macOS-latest,
          ubuntu-latest,
        ]

    steps:
      - uses: actions/checkout@v3

      - name: Set up Python ${{ matrix.python-version }}
        uses: actions/setup-python@v4
        with:
          python-version: ${{ matrix.python-version }}

https://github.com/hugovk/test/actions/runs/5057309868/workflow

Expected behavior:

3.12.0 beta 1 is installed:

• https://peps.python.org/pep-0693/#schedule

Actual behavior:

3.12.0 alpha 7 is installed:

• https://github.com/hugovk/test/actions/runs/5057309868/jobs/9075908996
• https://github.com/hugovk/test/actions/runs/5057309868/jobs/9075909144
• https://github.com/hugovk/test/actions/runs/5057309868/jobs/9075909318

There's no 3.12 beta in https://github.com/actions/python-versions/blob/main/versions-manifest.json

[dmitry-shibanov]

Hello @hugovk. Thank you for your report. We'll take a look on it.

[dmitry-shibanov]

Hello @hugovk. The Python 3.12.0-beta.1 was added. For now I'm going to close the issue.

[hugovk]

Confirmed, thank you! This will really help people test before the full release comes out in October, and make sure their own code is ready, and also help find bugs in Python itself. :)

[The-Compiler]

Beta 2 was released - will this need a manual update, or should that get pulled in automatically soon?

[nulano]

Looks like it should already be available: https://github.com/actions/python-versions/releases/tag/3.12.0-beta.2-5200633613

[The-Compiler]

So far, I still see the beta 1 being used:

Run actions/setup-python@v4
  with:
    python-version: 3.12-dev
    check-latest: false
    token: ***
    update-environment: true
    allow-prereleases: false
  env: [...]
Installed versions
  Version ~3.12.0-0 was not found in the local cache
  Version ~3.12.0-0 is available for downloading
  Download from "https://github.com/actions/python-versions/releases/download/3.12.0-beta.1-5076755295/python-3.12.0-beta.1-linux-22.04-x64.tar.gz"

But from what it looks like, actions/python-versions#232 should fix that soon!

edit: merged now!