rind 0.1.0a1

A minimal PEP 517 build backend for creating meta-packages

rind

A minimal PEP 517 build backend for creating meta-packages — packages that contain no code, only dependencies.

Why?

Sometimes you want to split a package into:

• mypackage-core: The actual code with minimal dependencies
• mypackage: A meta-package that installs mypackage-core plus recommended optional dependencies

This lets users choose between a lightweight install (pip install mypackage-core) or batteries-included (pip install mypackage), while both provide the same import mypackage experience.

Features

• Zero Python code in output: Wheels contain only .dist-info/ metadata
• Automatic version pinning: mypackage==1.2.3 always installs mypackage-core==1.2.3
• Metadata inheritance: Reuse authors, license, URLs from the core package's pyproject.toml
• Selective extras: Choose which extras to pass through vs. make required
• Single repository: Both packages live in the same repo, tagged together

Quick Start

Create a meta/ directory in your repository with this pyproject.toml:

[build-system]
requires = ["rind"]
build-backend = "rind"

[tool.rind]
# Inherit metadata from the core package
inherit-metadata = "../pyproject.toml"

# The meta-package name (the core package keeps the original name)
name = "mypackage"

# Extras from core to include as default dependencies
core-extras = ["recommended", "optional"]

# Extras to pass through (not included by default, but available)
passthrough-extras = ["test", "docs"]

Build both packages:

python -m build .        # Build mypackage-core
python -m build meta/    # Build mypackage (meta-package)

Configuration Reference

All options go in [tool.rind]:

Option	Required	Description
name	Yes	Name of the meta-package
inherit-metadata	No	Path to parent pyproject.toml to inherit from
description	No	Override inherited description
core-package	No	Core package name (default: inherited name or {name}-core)
core-extras	No	List of extras to include as required dependencies
passthrough-extras	No	List of extras to re-expose (with pinned versions)
additional-dependencies	No	Extra dependencies beyond the core package
version-root	No	Root for setuptools_scm (default: "..")

How Version Pinning Works

Both packages use setuptools_scm to get their version from git tags. When you tag a release:

git tag v1.2.3
python -m build .        # Creates mypackage_core-1.2.3-py3-none-any.whl
python -m build meta/    # Creates mypackage-1.2.3-py3-none-any.whl
                         # with Requires-Dist: mypackage-core==1.2.3

Since both builds use the same git state, versions always match.

Example: reproject

The reproject package uses this backend:

Root pyproject.toml (reproject-core):

[project]
name = "reproject-core"
dependencies = ["numpy", "astrofrog", "scipy"]  # minimal

[project.optional-dependencies]
dask = ["dask", "zarr"]
hips = ["pillow", "pyavm"]
test = ["pytest"]

meta/pyproject.toml (reproject):

[build-system]
requires = ["rind"]
build-backend = "rind"

[tool.rind]
inherit-metadata = "../pyproject.toml"
name = "reproject"
core-extras = ["dask", "hips"]        # Now required
passthrough-extras = ["test"]          # Still optional

Result:

• pip install reproject-core → minimal dependencies
• pip install reproject-core[dask] → adds dask support
• pip install reproject → full experience (core + dask + hips)
• pip install reproject[test] → full experience + test dependencies

License

BSD 3-Clause License. See LICENSE for details.