Backend 'setuptools.build_meta:__legacy__' is not available.

[smartalecH]

I'm working on building jaxlib from source. Everything compiles fine, but I get an error when trying to build the jaxlib wheel:

Backend 'setuptools.build_meta:__legacy__' is not available.

This is a pretty common issue when using pyproject-tools and build and when one forgets to specify the build-backend in the pyproject.toml for "complicated systems".

I noticed that the primary jax module has a pyproject.toml with the build-backend explicitly defined. But jaxlib is using a setup.py file, and its not obvious to me if I can somehow explicitly specify the build-backend this way? Any ideas on how I can circumvent this? Thanks so much!

[hawkinsp]

Does pip install setuptools fix the problem?

[smartalecH]

Thanks @hawkinsp, for chiming in! Yep I have that already in my env, but I get the same issue. I opened a REPL session just to make sure all the required dependencies were properly loaded.

I also tried manually adding the pyproject.toml file to the jaxlib build target dependencies in the bazel BUILD file, but that doesn't seem to help either.