"make python" is broken

[danfortunato]

The Python interface fails to build with make python. This can be fixed by deleting the pyproject.toml file, or by adding setuptools to pyproject.toml and removing the -e flag from pip install in the Makefile.

[lu1and10]

The Python interface fails to build with make python. This can be fixed by deleting the pyproject.toml file, or by adding setuptools to pyproject.toml and removing the -e flag from pip install in the Makefile.

Thanks for bring this up. It seems that with the latest pip and setuptools, even deleting the pyproject.toml file and use setup.py alone to install in editable mode also breaks(non-editable mode seems to be fine anyway).

We are using numpy.distutils as the build back end for the fortran python module ext, according to https://numpy.org/doc/stable/reference/distutils_status_migration.html, numpy.distutils is deprecated and only tested with setuptools < 60.0 , so if you apply the following patch and using setuptools==59.8.0. make python might work.

--- a/python/pyproject.toml
+++ b/python/pyproject.toml
@@ -1,3 +1,3 @@
 [build-system]
-requires = ["numpy"]
+requires = ["setuptools==59.8.0", "numpy"]

While as numpy.distutils is deprecated, it makes perfect sense that we should switch to meson or scikit-build-core following the migration advice https://numpy.org/doc/stable/reference/distutils_status_migration.html. We should keep the issue open till we switch to the new build back end.