how to get older version of setuptools

[cbk6028]

environment: Python 3.11.9 venv on Alpine Linux

I'm installing a package. The latest setuptools already removed _get_unpatched which is needed by that package so I tried to degrade the setuptools by pip install setuptools=18.3.2. Still failed to pip install that.
Then I dircetly modified the setup.py setup_requires=['setuptools==18.3.2'] and run pip install.
I get an error: conflict with the backend dependencies: setuptools==69.5.1 is incompatible with setuptools==18.3.2.

It seems that pip install doesn't use installed setuptools ?

[abravalheri]

Have you tried pinning the version in pyproject.toml's [build-system] requires = ...?

(The pyproject.toml of the package you are trying to build/install).

[cbk6028]

I don't find the pyproject.toml in it.

[abravalheri]

OK, in that case I suppose you can try pip install --no-build-isolation --no-use-pep517 .... You will also need to install all build dependencies manually, that includes wheel.

But if the package is that old and relies on a very old version of setuptools, there is a chance you need an old version of pip to make it work too.

[cbk6028]

OK, in that case I suppose you can try pip install --no-build-isolation --no-pep517 ....

I try the command but it outputs no such option: --no-pep517. I search online and it may be --no-use-pep517 ?
Also I try the --no-use-pep517, the result :

--no-use-pep517 error: It is not possible to use --no-use-pep517
without setuptools and wheel installed.

But if the package is that old and relies on a very old version of setuptools, there is a chance you need an old version of pip to make it work too.

_get_unpatched that is needed by the package is available when the version of setuptools is less than v68.0.0.

[abravalheri]

--no-use-pep517 error: It is not possible to use --no-use-pep517
without setuptools and wheel installed.

Exactly, that is why I said previously You will also need to install all build dependencies manually, that includes wheel. You need to manually install the version of setuptools that you want + all the build dependencies that you need (and that includes wheel), before trying to install the package.

[cbk6028]

Oh, yeah! Thanks! I think wheel is already installed before and actually only setuptools is installed😀.

And I'm confused that when pip install one package, with build-isolation does pip always not use installed dependents ?

[abravalheri]

In the future the idea is that pip will use build isolation by default. But for now, sometimes it does, sometimes is does not, it all depend on some internal pip heuristics.

You can read about build isolation in https://pip.pypa.io/en/stable/reference/build-system/pyproject-toml/#build-isolation, but it is basically equivalent of creating a brand new virtual environment just for running the build, and "re-installing" all the dependencies from scratch in this isolated build environment.

[abravalheri]

setuptools==18.3.2 😨