BLD: build failure with new setuptools 73.0.0

[tylerjereddy]

I don't think it is particularly surprising when this happens, but it did just bite me while working on the release/backports in gh-21362, and I confirmed that I can reproduce on main with setuptools 73.0.0, released an hour ago, via its interaction with pythran 0.16.0, 0.15.0, or 0.16.1 on MacOS ARM (didn't check other platforms).

[560/1283] Generating 'scipy/stats/_stats_pythran.cpython-312-darwin.so.p/_stats_pythran.cpp'
FAILED: scipy/stats/_stats_pythran.cpython-312-darwin.so.p/_stats_pythran.cpp 
/Users/treddy/python_venvs/py_312_scipy_dev2/bin/pythran -E ../scipy/stats/_stats_pythran.py -o scipy/stats/_stats_pythran.cpython-312-darwin.so.p/_stats_pythran.cpp
Traceback (most recent call last):
  File "/Users/treddy/python_venvs/py_312_scipy_dev2/bin/pythran", line 8, in <module>
    sys.exit(run())
             ^^^^^
  File "/Users/treddy/python_venvs/py_312_scipy_dev2/lib/python3.12/site-packages/pythran/run.py", line 190, in run
    pythran.compile_pythranfile(args.input_file,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/treddy/python_venvs/py_312_scipy_dev2/lib/python3.12/site-packages/pythran/__init__.py", line 127, in __getattr__
    import pythran.toolchain
  File "/Users/treddy/python_venvs/py_312_scipy_dev2/lib/python3.12/site-packages/pythran/toolchain.py", line 11, in <module>
    from pythran.dist import PythranExtension, PythranBuildExt
  File "/Users/treddy/python_venvs/py_312_scipy_dev2/lib/python3.12/site-packages/pythran/dist.py", line 142, in <module>
    class PythranBuildExt(PythranBuildExtMixIn, LegacyBuildExt, metaclass=PythranBuildExtMeta):
TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases
[575/1283] Compiling C++ object scipy/sparse/sparsetools/_sparsetools.cpython-312-darwin.so.p/bsr.cxx.o

python -m pip install "setuptools<73.0.0" in an affected environment suffices to fix the issue. I suspect this is an "upstream" matter, but perhaps worth noting at least. cc @serge-sans-paille just in case maybe, though perhaps setuptools will yank if it is a problem on their end.

[tylerjereddy]

This hack does seem to help isolated builds deal with the transitive dep issue locally, but is obviously very undesirable:

--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,6 +28,7 @@ requires = [
     # The upper bound on pythran is pre-emptive only; 0.16.1
     # is released/working at time of writing.
     "pythran>=0.14.0,<0.17.0",
+    "setuptools<73.0.0", # hack to work around gh-21416

So, hopefully gets resolved/yanked upstream.

[tommilligan]

Thanks for the above investigation and fix - I've opened an issue and proposed a fix to pythran upstream here: serge-sans-paille/pythran#2229

[rgommers]

xref serge-sans-paille/pythran#2228 (comment) for context

[agriyakhetarpal]

I just bisected, and the first bad commit in setuptools seems to be f9398b1f. I'll have a look and try to write a bug report for this there.

cross-posted from serge-sans-paille/pythran#2228

[agriyakhetarpal]

Upstream issue: pypa/setuptools#4579 (as linked above).

[agriyakhetarpal]

New tag: https://github.com/pypa/setuptools/releases/tag/v73.0.1

[agriyakhetarpal]

This can now be closed since https://pypi.org/project/setuptools/73.0.1/ is now up.

[tylerjereddy]

@agriyakhetarpal Thanks for the hard work bisecting and coordinating upstream with setuptools for us.

I see the issue fixed locally as well, with the newly-released setuptools 73.0.1.