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

> if this turns out to be a viable fix, what are the next steps?

Shout it from the mountain? :-)

I'd document it in my working notes in case the change gets wiped out by 
a new version or what have you.

If there's a way to test for the change in your own code before creating 
the utils, those notes could be in your error message.

Otherwise, follow the code norms of your organization.

I'd also use the issue as a door to the open source world - join the 
list if you haven't, comment on the bug discussion if you have something 
to add, and so on.

Bill

-- 

https://github.com/phobrain/phobrain

Phobrain.com

On 2026-01-07 20:25, Samuel H Dupree Jr wrote:

> Thanks for passing on the link referenced below. I'm presently testing 
> the mod, and so far it works. The question I have at present is, if 
> this turns out to be a viable fix, what are the next steps?
> 
> Sam Dupree
> 
> On Tue, 06 Jan 2026 10:10:29 -0800, Bill Ross 
> <[email protected]> wrote:
> 
> Here it is - the diffs are reached by clicking on the hex-coded links 
> ("Long time I fell ..." --Gandalf).
> 
> https://github.com/numpy/numpy/pull/27406/commits/1cc02cc6710384c52e1082a33d1617504eaed296
> 
> ---
> --
> 
> Phobrain.com
> 
> On 2026-01-06 09:37, Bill Ross wrote:
> 
> I'm out of my depth, but I'd try that location first, however maybe 
> like this:
> 
> if name == "meson":
> from ._meson import MesonBackend
> return MesonBackend
> elif name == "distutils":
> 
> print("HACK skipping distutils for buggy downstream import")
> 
> return None
> 
> #    from ._distutils import DistutilsBackend
> #    return DistutilsBackend
> else:
> raise ValueError(f"Unknown backend: {name}")
> 
> If it runs great, if not, it appears DistUtilsBackend would need to 
> skip loading that specific compiler.
> 
> I don't understand how to find the actual patch/diff that the bug link 
> is about.
> 
>> Might try using the patch in 
>> https://github.com/numpy/numpy/pull/27406.
> 
> ---
> --
> 
> Phobrain.com
> 
> On 2026-01-06 09:23, Samuel H Dupree Jr wrote:
> 
> Are you saying that I should try modifying 
> ~/opt/anaconda3/lib/python3.11/site-packages/numpy/f2py/_backends/-init_.py, 
> as follows:
> 
> 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,
> 
> Please advise.
> 
> Sam Dupree.
> 
> On Tue, 06 Jan 2026 09:14:47 -0800, Bill Ross 
> <[email protected]> wrote:
> 
>> 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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