I'm from Nebraska. Unfortunately if your Python is compiled in a datacenter in Iowa, it's more likely that it was powered with wind energy. Claim: Iowa has better Clean Energy PPAs for datacenters than Nebraska (mostly due to rational wind energy subsidies).

Anyways, software supply chain security and Python & package build signing and then containers and signing them too

Conda-forge's builds are probably faster than the official CPython builds. conda-forge/python-feedstock//recipe/meta.yml: https://github.com/conda-forge/python-feedstock/blob/main/re...

Conda-forge also has OpenBLAS, blos, accelerate, netlib, and Intel MKL; conda-forge docs > switching BLAS implementation: https://conda-forge.org/docs/maintainer/knowledge_base/#swit...

From "Building optimized packages for conda-forge and PyPI" at EuroSciPy 2024: https://pretalx.com/euroscipy-2024/talk/JXB79J/ :

> Since some time, conda-forge defines multiple "cpu-levels". These are defined for sse, avx2, avx512 or ARM Neon. On the client-side the maximum CPU level is detected and the best available package is then installed. This opens the doors for highly optimized packages on conda-forge that support the latest CPU features.

> We will show how to use this in practice with `rattler-build`

> For GPUs, conda-forge has supported different CUDA levels for a long time, and we'll look at how that is used as well.

> Lastly, we also take a look at PyPI. There are ongoing discussions on how to improve support for wheels with CUDA support. We are going to discuss how the (pre-)PEP works and synergy possibilities of rattler-build and cibuildwheel

Linux distros build and sign Python and python3-* packages with GPG keys or similar, and then the package manager optionally checks the per-repo keys for each downloaded package. Packages should include a manifest of files to be installed, with per-file checksums. Package manifests and/or the package containing the manifest should be signed (so that tools like debsums and rpm --verify can detect disk-resident executable, script, data asset, and configuration file changes)

virtualenvs can be mounted as a volume at build time with -v with some container image builders, or copied into a container image with the ADD or COPY instructions in a Containerfile. What is added to the virtualenv should have a signature and a version.

ostree native containers are bootable host images that can also be built and signed with a SLSA provenance attestation; https://coreos.github.io/rpm-ostree/container/ :

rpm-ostree rebase ostree-image-signed:registry:<oci image>
rpm-ostree rebase ostree-image-signed:docker://<oci image>

> Fetch a container image and verify that the container image is signed according to the policy set in /etc/containers/policy.json (see containers-policy.json(5)).

So, when you sign a container full of packages, you should check the package signatures; and verify that all package dependencies are identified by the SBOM tool you plan to use to keep dependencies upgraded when there are security upgrades.

e.g. Dependabot - if working - will regularly run and send a pull request when it detects that the version strings in e.g. a requirements.txt or environment.yml file are out of date and need to be changed because of reported security vulnerabilities in ossf/osv-schema format.

Is there already a way to,
as a developer, sign Python packages built with cibuildwheel with Twine and TUF or sigstore to be https://SLSA.dev/ compliant?