Dependencies from `get_requires_for_build_sdist` are not installed in isolated environment

[Carreau]

It seem the with the latest version of build; setuptools-scm decides that my project version is always 0.0.0; is that expected ? I found other issues mentioning setutools-scm, but it seem more targeted toward adopting setuptools-scm for build itself. Anly pointer on how to fix this beyond not using 0.1 ?

See zarr-developers/zarr-python#666

[layday]

This isn't an issue with build; you haven't added setuptools-scm to your pyproject.toml requires. I presume because setuptools is invoked through PEP 517 it does not honour setup_requires.

[gaborbernat]

Yeah, you actually need to specify your build dependencies in pyproject.toml.

What you have https://github.com/zarr-developers/zarr-python/blob/master/pyproject.toml#L2, and what you should https://github.com/pypa/virtualenv/blob/main/pyproject.toml#L5

setup_requires is deprecated and has been for a long time now.

[layday]

Upon closer inspection setuptools should return its setup_requires from get_requires_for_build_x. Are we not installing the dependencies from get_requires before building a distribution in an isolated environment?

[layday]

I'm reopening this because it seems like a legitimate issue with isolated builds. According to PEP 517:

The build_sdist hook is executed in an environment which contains the bootstrap requirements from pyproject.toml and those specified by the get_requires_for_build_sdist hook.

We'll probably want to install these after the build_dependencies in _build_in_isolated_env:

build/src/build/__main__.py

Line 53 in b39dcdd

env.install(builder.build_dependencies)

Thanks for reporting, @Carreau.

[FFY00]

Fixed in 260c518.