How to contribute

We'd love to accept your patches and contributions to this project. There are just a few small guidelines you need to follow.

Contributor License Agreement

Contributions to this project must be accompanied by a Contributor License Agreement. You (or your employer) retain the copyright to your contribution, this simply gives us permission to use and redistribute your contributions as part of the project. Head over to https://cla.developers.google.com/ to see your current agreements on file or to sign a new one.

You generally only need to submit a CLA once, so if you've already submitted one (even if it was for a different project), you probably don't need to do it again.

Code reviews

All submissions, including submissions by project members, require review. We use GitHub pull requests for this purpose. Consult GitHub Help for more information on using pull requests.

Generated files

Some checked-in files are generated and need to be updated when a new PR is merged.

Documentation

To regenerate the content under the docs/ directory, run this script in the repository root:

./update_docs.sh

This needs to be done whenever the docstrings in the corresponding .bzl files are changed; see docs/BUILD.

Precompiled tools

The packaging rules depend on two precompiled binaries, tools/piptool.par and tools/whltool.par. We need these to be precompiled because they are invoked during WORKSPACE evaluation, before Bazel itself is able to build anything from source. The .par files can be regenerated by running this script in the repository root:

# You can pass --nodocker if Docker is not available on your system.
./update_tools.sh

This needs to be done whenever the corresponding sources in the packaging/ directory are updated.

Since these are binary files and therefore unreviewable, for security reasons¹ we will regenerate the .par files for you when merging your pull request.

¹ See "Reflections on Trusting Trust".

Core rules

The bulk of this repo is owned and maintained by the Bazel Python community. However, since the core Python rules (py_binary and friends) are still bundled with Bazel itself, the Bazel team retains ownership of their stubs in this repository. This will be the case at least until the Python rules are fully migrated to Starlark code.

Practically, this means that a Bazel team member should approve any PR concerning the core Python logic. This includes everything under the python/ directory except for pip.bzl, whl.bzl, and requirements.txt.

Issues should be triaged as follows:

Anything concerning the way Bazel implements the core Python rules should be filed under bazelbuild/bazel, using the label team-Rules-python.
If the issue specifically concerns the rules_python stubs, it should be filed here in this repository and use the label core-rules.
Anything else, such as feature requests not related to existing core rules functionality, should also be filed in this repository but without the core-rules label.