CIBuildWheel repository.

Recipes and continuous integration (CI) to build musllinux (Alpine) wheels for Python packages that don't provide them on PyPI. Built with cibuildwheel and hosted on Cloudsmith.

Layout

Path	Purpose
build.yaml	Python versions and architectures every recipe is built for
recipes/<name>/recipe.yaml	One package: version, system packages, build environment, test
scripts/wheels.py	Works out what is missing from the index and builds it
.github/workflows/ci.yaml	Runs the script and uploads the result

How it works

CI compares what should exist (every recipe × Python version × architecture) against the Cloudsmith index and builds only what is missing. Pull requests build the missing wheels as a check; pushes to master build and upload them. Nothing else triggers a build, so every task below is a one-line change.

Add or change a Python version

Edit the python list in build.yaml. Every recipe is built and uploaded for the new version.

Update a package

Change version in its recipe.yaml. Renovate opens these PRs automatically.

Follow another package's requirement

When one recipe limits which versions of another it accepts (borgbackup caps msgpack), replace version with version_from:

name: msgpack
version_from: borgbackup   # recipe directory name

The newest release that recipe's requirement allows is built, so it moves on its own when the other package is updated. wheels.py plan --force shows the version chosen.

Add a package

Create recipes/<name>/recipe.yaml, where <name> matches the PyPI name:

---
name: borgbackup
version: "1.4.5"        # quoted; the sdist is downloaded from PyPI

apk:                    # Alpine packages the build needs, each with its reason
  - openssl-dev         # libcrypto

environment:            # optional: extra environment variables for the build
  SOME_FLAG: "1"

test: borg --version    # optional: run against each built wheel

Rebuild everything

Run the workflow manually from the Actions tab with force ticked.

Working out what a recipe needs

The apk list is the complete set of system packages for a build. The musllinux image already ships gcc, g++, make, pkgconf and linux-headers, so list only the -dev packages for libraries the package links against (see its setup.py or build documentation).

To check a list, build locally. A package is needed if removing its line makes the build or the test command fail:

pip install -r scripts/requirements.txt
python scripts/wheels.py build borgbackup --python 3.15 --arch x86_64

This needs Docker. Wheels are written to wheelhouse/. Building an architecture other than the host's also needs QEMU (docker run --privileged --rm tonistiigi/binfmt --install all).

To see what CI would build right now:

python scripts/wheels.py plan