Can't find numpy package build error

[sean-engelstad]

Numpy import error when building funtofem after make interface step found by @A-CGray.

pip install -e .
Obtaining file:///home/sengelstad6/git/funtofem
  Preparing metadata (setup.py) ... error
  error: subprocess-exited-with-error
  
  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [6 lines of output]
      Traceback (most recent call last):
        File "<string>", line 2, in <module>
        File "<pip-setuptools-caller>", line 34, in <module>
        File "/home/sengelstad6/git/funtofem/setup.py", line 6, in <module>
          import numpy
      ModuleNotFoundError: No module named 'numpy'
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.
make: *** [Makefile:37: interface] Error 1

@sean-engelstad (myself) found a solution to this issue with the following conda installation steps. Should we add a note to the README about this or is there another fix?
Pre-build steps

conda create -n F2F python=3.8
conda activate F2F
conda install -c conda-forge numpy mpi4py cython
conda install gxx_linux-64=9.3.0 -q -y

Then you either do the real build

cd ~/git/funtofem
make clean
make
make interface

Or the complex-mode build

cd ~/git/funtofem
make clean
make complex
make complex_interface

[A-CGray]

I think @timryanb might be able to help out here since TACS has pretty much exactly the same build process and I don't have this issue there. I don't use conda so the proposed solution here wouldn't fix my issue, numpy probably just needs to be specified as a build dependency somewhere

[A-CGray]

Adding the pyproject.toml file from the TACS repo to F2F fixes the issue:

#pyproject.toml
[build-system]
# Minimum requirements for the build system to execute.
requires = ['setuptools>=45.0', 'wheel', 'cython>=0.29', 'oldest-supported-numpy', 'mpi4py==3.1.1']

[sean-engelstad]

That sounds like a much better solution, I'll add it to that PR

[sean-engelstad]

Added this pyproject.toml to the PR on moving pyfuntofem into funtofem. Linking this issue with the PR.