Can I constraint build requirements with uv build?

[notatallshaw]

I tried using the new uv build with a pyproject.toml that looks like this:

[build-system]
requires = ["setuptools==74.1.1", "wheel==0.44.0"]
build-backend = "setuptools.build_meta"

[project]
name = "minimal_project"
version = "0.1.0"

I created a build-constraints.txt file that looks like this (the versions contradict the build requires and hashes are purposefully wrong):

setuptools==69.0.0 --hash=sha256:fc91b5f89e392ef5b77fe143b17e32f65d3024744fba66dc3afe07201684d766
wheel==0.40.0 --hash=sha256:2376a90c98cc337d18623527a97c31797bd02bad0033d41547043a1cbfbe4481

I then set UV_BUILD_CONSTRAINT to point to my build-constraints.txt, and then I ran uv build ., but I did not get an error that these versions or hashes are wrong.

Is there a way to constrain build requirements during building? I specifically think of scenarios where I don't control the contents of an sdist, or there are recursive build requirements I want to constrain.

[charliermarsh]

It's not supported yet but I'll probably do it today. I think it's covered in #7065.