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Subject: Re: python-numpy (1.22.0-1) can't be imported
Date: Sun, 06 Feb 2022 12:35:36 -0500
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On Sat, Jan 22 2022, Masamichi Hosoda wrote:

>> It is something like that, but "-Wl,--export-all-symbols"
>> is not used on 1.21.4 and is not needed for most of the other
>> modules on 1.22.x
>> 
>> so I am looking for a less extreme action.
>> Also to understand how it can impact other python subpackages
>
> If I understand correctly, I've found the root cause of the issue.
> I've sent a pull request to numpy.
> https://github.com/numpy/numpy/pull/20874

Based on that pull request, it looks like it's related to the patches
used to avoid python C-extension modules with only one exported function
mentioned a year ago:
https://cygwin.com/pipermail/cygwin/2021-January/247211.html
https://cygwin.com/pipermail/cygwin/2021-January/247216.html
From a glance at the Python C API docs, it looks like Python C extension
modules are supposed to have only one exported function:
https://docs.python.org/3/extending/extending.html#the-module-s-method-table-and-initialization-function
https://docs.python.org/3/extending/extending.html#providing-a-c-api-for-an-extension-module

The NumPy CFFI tests seem to want to use a few C extension modules as
normal shared libraries, which requires that the functions the tests
want to use to be exported from the DLL, but this seems to be a somewhat
unusual case.

I tend to compile my own versions of Cython (without patches), which may
have been picked up when I compiled the new version of NumPy.


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