Proper clean-up hook usable with pyproject-build

[ericzolf]

After having read https://blog.ganssle.io/articles/2021/10/setup-py-deprecated.html and having already introduced a working pyproject.toml, I'm in the process of replacing all invocations of ./setup.py with pyproject-build aka python -m build.

So far so good, but I have custom build/clean steps in my ./setup.py and I've noticed that at least the cleaning step(s) doesn't work, the generated files aren't removed after the sdist/wheel have been built, and pyproject-build doesn't have an explicit clean "target". The build step(s) seem to work correctly, but I also don't know how much is due to luck.

Any hint on how to fix my plug-ins would be appreciated.

[abravalheri]

Hi @ericzolf, is it possible for you to implement a clean task using a task runner like tox, nox, pydoit, invoke? (or any task runner really...)

One thing that I find very useful is to use git clean -fdx (or a variation using -X, -e, etc...) to remove files that are not tracked by git.

[webknjaz]

I'd like to share that I'm making in-tree build backends for projects with C-extensions and I recently tried out an idea of building in a temporary directory. So I included some logic into my setuptools wrapper to copy files to a tmp directory for non-editable builds. This lets me be sure I haven't accidentally included any garbage into the wheel + doesn't populate generated files into my dev env in such cases: https://github.com/aio-libs/yarl/blob/8d28329/packaging/pep517_backend/_backend.py#L284-L293.

[ericzolf]

Hi @ericzolf, is it possible for you to implement a clean task using a task runner like tox, nox, pydoit, invoke? (or any task runner really...)

That could be an approach, but I thought to keep it in the back-end. This remark though makes me think that I might be poking in the wrong place: the back-end (setuptools) already knows how to clean-up, it's possibly rather the front-end (build) which doesn't use it properly.

One thing that I find very useful is to use git clean -fdx (or a variation using -X, -e, etc...) to remove files that are not tracked by git.

Not an option in this case, I need something more specific, I can't risk lose all local changes each time I want to clean-up the build.

[abravalheri]

For now, the definition of PyPA for backend APIs does not include clean hooks. This might need to be discussed in the Python discourse.

[ericzolf]

Thanks, I'm then continuing the discussion at https://discuss.python.org/t/custom-build-targets-for-cleanup-post-pep-518/13741/32