Re: How to handle ModuleNotFoundError: No module named 'distutils.msvccompiler' on Mac OSX (Intel) using f2py?

> So, what do you think the best way is to fix my problem?

Per Charles Harris, stub out the missing OS, which distutils seems to 
try to load by default (i.e. the key is 'distutils' not the unwanted OS 
so my idea wasn't fruitful):

> Might try using the patch in https://github.com/numpy/numpy/pull/27406.

Bill Ross

--

Phobrain.com

On 2026-01-06 08:49, Samuel H Dupree Jr wrote:

> The source member, 
> ~/opt/anaconda3/lib/python3.11/site-packages/numpy/f2py/_backends/-init_.py,
> 
> def f2py_build_generator(name):
> if name == "meson":
> from ._meson import MesonBackend
> return MesonBackend
> elif name == "distutils":
> from ._distutils import DistutilsBackend
> return DistutilsBackend
> else:
> raise ValueError(f"Unknown backend: {name}")
> 
> appears to be where the "key" is chosen, furthermore, in f2p2e.py sets 
> the background_key and invokes 2py_build_generator. To my knowledge, 
> I'm not running meson. So, what do you think the best way is to fix my 
> problem?
> 
> Please advise,
> 
> Sam Dupree
> 
> On Sun, 04 Jan 2026 18:23:22 -0800, Bill Ross 
> <[email protected]> wrote:
> 
> Uninformed debugging:
> 
>> build_backend = f2py_build_generator(backend_key)
> 
> Can you inspect that backend_key? It seems  like it could be 'key' to 
> choosing the wrong back end.
> 
> Bill
> 
> --
> 
> Phobrain.com
> 
> On 2026-01-04 17:18, Samuel H Dupree Jr wrote:
> 
>> I am resurrecting a Python program I wrote a few years under Python 
>> 3.9. I'm presently:
>> 
>> * Running Python 3.11 under Mac OSX Sequoia (ver. 15.7.1)
>> * Using NumPy version 1.26.4
>> * Running on an Intel (x86-64) Mac Pro Desktop (2019)
>> *
>> 
>> The program uses a Fortran 77 subroutine that was wrapped using f2py 
>> when I running Python 3.9. However, when I attempt to wrap that same 
>> subroutine (the source code is attached to this note) using f2py in 
>> Python 3.11, I get the following error message.
>> 
>> (base) user@Mac-Pro accgravityfiled_builder_f2py % _f2py -c 
>> accgravityfield.f  -m accgravityfield _
>> Traceback (most recent call last):
>> File "/Users/user/opt/anaconda3/bin/f2py", line 8, in <module>
>> sys.exit(main())
>> ^^^^^^
>> File 
>> "/Users/user/opt/anaconda3/lib/python3.11/site-packages/numpy/f2py/f2py2e.py", 
>> line 766, in main
>> run_compile()
>> File 
>> "/Users/user/opt/anaconda3/lib/python3.11/site-packages/numpy/f2py/f2py2e.py", 
>> line 594, in run_compile
>> build_backend = f2py_build_generator(backend_key)
>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> File 
>> "/Users/user/opt/anaconda3/lib/python3.11/site-packages/numpy/f2py/_backends/__init__.py", 
>> line 6, in f2py_build_generator
>> from ._distutils import DistutilsBackend
>> File 
>> "/Users/user/opt/anaconda3/lib/python3.11/site-packages/numpy/f2py/_backends/_distutils.py", 
>> line 3, in <module>
>> from numpy.distutils.core import setup, Extension
>> File 
>> "/Users/user/opt/anaconda3/lib/python3.11/site-packages/numpy/distutils/core.py", 
>> line 24, in <module>
>> from numpy.distutils.command import config, config_compiler, \
>> File 
>> "/Users/user/opt/anaconda3/lib/python3.11/site-packages/numpy/distutils/command/config.py", 
>> line 19, in <module>
>> from numpy.distutils.mingw32ccompiler import generate_manifest
>> File 
>> "/Users/user/opt/anaconda3/lib/python3.11/site-packages/numpy/distutils/mingw32ccompiler.py", 
>> line 27, in <module>
>> from distutils.msvccompiler import get_build_version as 
>> get_build_msvc_version
>> ModuleNotFoundError: No module named 'distutils.msvccompiler'
>> (base) user@Mac-Pro accgravityfiled_builder_f2py %
>> 
>> As for gfortran is concerned:
>> 
>> (base) user@Mac-Pro accgravityfiled_builder_f2py % gfortran -v
>> Using built-in specs.
>> COLLECT_GCC=gfortran
>> COLLECT_LTO_WRAPPER=/usr/local/Cellar/gcc/15.2.0/bin/../libexec/gcc/x86_64-apple-darwin24/15/lto-wrapper
>> Target: x86_64-apple-darwin24
>> Configured with: ../configure --prefix=/usr/local/opt/gcc 
>> --libdir=/usr/local/opt/gcc/lib/gcc/current --disable-nls 
>> --enable-checking=release --with-gcc-major-version-only 
>> --enable-languages=c,c++,objc,obj-c++,fortran --program-suffix=-15 
>> --with-gmp=/usr/local/opt/gmp --with-mpfr=/usr/local/opt/mpfr 
>> --with-mpc=/usr/local/opt/libmpc --with-isl=/usr/local/opt/isl 
>> --with-zstd=/usr/local/opt/zstd --with-pkgversion='Homebrew GCC 
>> 15.2.0' --with-bugurl=https://github.com/Homebrew/homebrew-core/issues 
>> --with-system-zlib --build=x86_64-apple-darwin24 
>> --with-sysroot=/Library/Developer/CommandLineTools/SDKs/MacOSX15.sdk
>> Thread model: posix
>> Supported LTO compression algorithms: zlib zstd
>> gcc version 15.2.0 (Homebrew GCC 15.2.0)
>> (base) user@Mac-Pro accgravityfiled_builder_f2py %
>> 
>> I have two questions:
>> 
>> * Why is f2py in a Mac OSX Intel based environment attempting to 
>> import '_distutils.msvccompiler_' that is required for Windows' 
>> environment only?
>> * What do I need to do to eliminate this problem?
>> 
>> Any thoughts?
>> 
>> Sam Dupree
>> 
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