CPython Windows Builder (GitHub Actions)

This repository provides a simple GitHub Actions workflow to build CPython for Windows (x64) from the official source tarballs on python.org.

You trigger the workflow manually, pass in a version like 3.12.10 or 3.12.12, and the pipeline will:

1. Download the matching CPython source from https://www.python.org/ftp/python/…
2. Build CPython with the official PCbuild scripts (Release / x64)
3. Collect the build outputs
4. Pack them into a highly compressed .7z
5. Upload the .7z as an artifact
6. Create a GitHub Release with the .7z attached

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Workflow: Build CPython (Windows)

The workflow file is located at:

.github/workflows/build-cpython.yml

It is triggered manually via workflow_dispatch and exposes one input:

• python_version – CPython version to build

  • Example: 3.12.10, 3.12.12

Internally, this value is used to construct:

• Download URL: https://www.python.org/ftp/python/<python_version>/Python-<python_version>.tgz
• Source directory: Python-<python_version>
• Output archive name: cpython-<python_version>-win64.7z
• Release tag: v<python_version>-win64

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How to Use

1. Enable GitHub Actions for this repository (if not already enabled).

2. Go to the Actions tab in GitHub.

3. Select “Build CPython (Windows)” workflow.

4. Click “Run workflow”.

5. In the dialog:

   • Fill in python_version, e.g. 3.12.12.
   • Click “Run workflow”.

GitHub Actions will spin up a windows-latest runner and:

• Download & extract the source.

• Run:

  • get_externals.bat
  • build.bat -c Release -p x64

• Copy build outputs from PCbuild\amd64\ into output\.

• Compress output\ into: cpython-<version>-win64.7z

• Upload the .7z as an artifact.

• Create a Release with:

  • Tag: v<version>-win64
  • Name: CPython <version> for Windows x64
  • Asset: cpython-<version>-win64.7z

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Outputs

After a successful run, you will have:

1. Actions artifact

   • Name: cpython-<version>-win64
   • File: cpython-<version>-win64.7z

2. GitHub Release

   • Tag: v<version>-win64
   • Title: CPython <version> for Windows x64
   • Attached asset: cpython-<version>-win64.7z

The .7z archive contains the built CPython binaries and related files from PCbuild\amd64\.

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Notes & Limitations

• Target platform: Windows x64 (-p x64 in build.bat).

• Build type: Release (-c Release).

• The workflow uses the official CPython Windows build system (PCbuild).

• This is not an official distribution; it is intended for:

  • Personal use
  • Testing new patch versions
  • Custom runtimes built from upstream source