> In practice, if you want to build the packages now available on PyPI, you will not be able to come up with a single tool that can build every one of them, probably, not even half of them.

This is the entire point of build backends, and is no longer true/hasn’t been true for several years. Build backends are not perfect, but they are the reason you can run `uv add` or `pip install` and get a functional wheel from an sdist on PyPI regardless of whether the sdist contains Python, C++, Rust, or anything else.

(This is now the second time you’ve imputed dishonesty in a conversation where I’ve tried to be helpful. So this will be my last response.)

You are absolutely delusional. None of what you write is true.

> This is the entire point of build backends

This is false. Python doesn't have any format, any way of describing how to compile a package. There's a gaping void where such a specification should be. Every tool that does it, has its own bespoke way of configuring it. Most of them don't even care what PyPA has to say about it.

> is no longer true/hasn’t been true for several years.

This has been true as recently as this morning. Nothing has changed in the last twenty years, probably more. No change is planned. The people who put themselves in charge of the process are incompetent to the point that, just like you, they don't understand the assignment and produce piles of worthless garbage instead.

> Build backends are not perfect

Build backends is a nonsense invented by PyPA because they didn't understand what actually needs to be done. The whole concept is worthless. It doesn't address the issue: it doesn't have a generic method describing how to build a Python package. Python doesn't need build backends. This whole circus needs to go.

> you can run `uv add` or `pip install` and get a functional wheel

This has nothing to do with building packages. Ideally, these are supposed to install the already built packages. If, however, you accidentally veered into the "oh, crap, I have to build it now because for my platform there isn't a binary", then pip or uv will poop their pants about 50% of the time because the tool that is needed to build the package is not installed, or the dependencies are missing, or the wrong version of the tool is installed, or it's misconfigured etc.

Worse yet, they shouldn't build anything. This is a batshit idiotic idea that a package installer, by default, tries to build a package if a binary is missing. But, we live in the world populated by people without a drop of critical thinking, governed by worshiping tradition, and that's why these tools do what they do.