numpy support broken under PIP 25.3 due to loss of support for setup.py bdist_wheel

[jhubbardnso]

Describe the problem
Installing JEP 4.2.0 via pip install --no-cache-dir -r requirements.txt with pip 25.3 leads to an installation without numpy support. Forcing the pip version back to 25.2 gets things working again. Building under 25.2 does include the following warning:

DEPRECATION: Building 'jep' using the legacy setup.py bdist_wheel mechanism, which will be removed in a future version. pip 25.3 will enforce this behaviour change. A possible replacement is to use the standardized build interface by setting the `--use-pep517` option, (possibly combined with `--no-build-isolation`), or adding a `pyproject.toml` file to the source tree of 'jep'. Discussion can be found at https://github.com/pypa/pip/issues/6334

Search for existing solutions
#574 partially addressed this by recommending that people build with --no-cache-dir and --no-build-isolation (but it does say that this isn't strictly necessary). I think that --no-build-isolation is now required with --no-cache-dir only needed after a broken version has been cached.

Environment (please complete the following information):
Ubuntu Linux 24.04
Python 3.12
PIP 25.3
JEP 4.2.0 and JEP 4.2.2
JDK 21

Additional context
IMO at minimum the README should be updated to note that --no-build-isolation is required to get proper numpy support. I haven't tested it yet, but alternatively maybe calling out that --use-pip517 is required might be better.
It would be nice if the changes mentioned in pypa/pip#6334 were applied to the JEP package so that it was no longer relying on deprecated build stuffs.

[bsteffensmeier]

I have made considerable changes to the build system for the upcoming 4.3 release of Jep that I believe will solve your problems. This includes requiring numpy to build jep and adding pyproject.toml. You can see those changes on the dev_4.3 branch and you can check out that branch if you would like to try it for yourself. I will be officially releasing Jep 4.3 as soon as I find time to build and test the release artifacts, hopefully in the next few weeks.

[jhubbardnso]

@bsteffensmeier thanks for the quick response. It's great to hear that a 4.3 is close. My python-fu isn't the greatest but hopefully @svensk-pojke can test the 4.3 dev branch in our environment and let you know that it works.

[jhubbardnso]

I haven't found a chance to test this yet but it looks like #586 should address this issue. I hope to find time later this week to test and hopefully I'll be able to close this ticket then.