Different files included in wheels between hatch build and build from other tools

[mkniewallner]

Using include on build targets, I end up with different files included in the final wheel depending on if the build is made with hatch build or through another tool (e.g. build or uv build).

• hatch version: 1.14.0
• reproduction repository: https://github.com/mkniewallner/repro-hatch-wheel-diff

Minimal reproducing example from the repository above:

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[project]
name = "foo"
version = "0.0.1"
description = ""
authors = []
requires-python = "~=3.10"

[tool.hatch.build.targets.sdist]
include = ["sdist.py", "sdist_wheel.py"]

[tool.hatch.build.targets.wheel]
include = ["sdist_wheel.py", "wheel.py"]

• Building with hatch:

$ uvx [email protected] build && echo "---sdist---" && tar -tzf dist/foo-0.0.1.tar.gz && echo "---wheel---" && unzip -l dist/foo-0.0.1-py3-none-any.whl
[...]
---sdist---
foo-0.0.1/sdist.py
foo-0.0.1/sdist_wheel.py
foo-0.0.1/pyproject.toml
foo-0.0.1/PKG-INFO
---wheel---
Archive:  dist/foo-0.0.1-py3-none-any.whl
  Length      Date    Time    Name
---------  ---------- -----   ----
        0  02-02-2020 00:00   sdist_wheel.py
        0  02-02-2020 00:00   wheel.py
       71  02-02-2020 00:00   foo-0.0.1.dist-info/METADATA
       87  02-02-2020 00:00   foo-0.0.1.dist-info/WHEEL
      322  02-02-2020 00:00   foo-0.0.1.dist-info/RECORD
---------                     -------
      480                     5 files

• Building with build (same result for uv build):

$ uvx --from [email protected] python -m build && echo "---sdist---" && tar -tzf dist/foo-0.0.1.tar.gz && echo "---wheel---" && unzip -l dist/foo-0.0.1-py3-none-any.whl
[...]
---sdist---
foo-0.0.1/sdist.py
foo-0.0.1/sdist_wheel.py
foo-0.0.1/pyproject.toml
foo-0.0.1/PKG-INFO
---wheel---
Archive:  dist/foo-0.0.1-py3-none-any.whl
  Length      Date    Time    Name
---------  ---------- -----   ----
        0  02-02-2020 00:00   sdist_wheel.py
       71  02-02-2020 00:00   foo-0.0.1.dist-info/METADATA
       87  02-02-2020 00:00   foo-0.0.1.dist-info/WHEEL
      260  02-02-2020 00:00   foo-0.0.1.dist-info/RECORD
---------                     -------
      418                     4 files

With hatch build, wheel.py is included in the wheel, but when invoking build backend through build (or uv build), it is not.

If I update include in [tool.hatch.build.targets.sdist] to include wheel.py, like so:

[tool.hatch.build.targets.sdist]
include = ["sdist.py", "sdist_wheel.py", "wheel.py"]

then when building with build (or uv build), the wheel will include wheel.py.

So it looks like when using another build backend, files included in the wheel that are not also in the sdist are not included.

[wshanks]

The behavior you are seeing is coming from the fact that python -m build builds an sdist and then builds a wheel from this sdist. Other tools like hatch, pip, and tox support building a wheel directly from the source code, skipping the sdist, so files not included in the sdist can still appear in the wheel.