[Numpy-discussion] Does numpy depend upon a Fortran library?

[Ralf Gommers]

On Wed, Jan 30, 2019 at 5:19 PM Charles R Harris <charlesr.harris at gmail.com>
wrote:

>
>
> On Wed, Jan 30, 2019 at 5:28 PM Marc F Paterno <paterno at fnal.gov> wrote:
>
>> Hello,
>>
>> I have encountered a problem with a binary incompatibility between the
>> Fortran runtime library installed with numpy when using 'pip install --user
>> numpy', and that used by the rest of my program, which is built using
>> gfortran from GCC 8.2.  The numpy installation uses libgfortran.5.dylib,
>> and GCC 8.2 provides libgfortran.5.dylib.
>>
>> While investigating the source of this problem, I downloaded the numpy
>> source
>> (
>> https://files.pythonhosted.org/packages/04/b6/d7faa70a3e3eac39f943cc6a6a64ce378259677de516bd899dd9eb8f9b32/numpy-1.16.0.zip
>> ),
>> and tried building it. The resulting libraries have no coupling to any
>> Fortran library that I can find.  I can find no Fortran source code files
>> in the numpy source,
>> except in tests or documentation.
>>
>> I am working on a MacBook laptop, running macOS Mojave, and so am using
>> the Accelerate framework to supply BLAS.
>>
>> I do not understand why the pip installation of numpy includes a Fortran
>> runtime library. Can someone explain to me what I am missing?
>>
>>
> That's interesting, it looks like the wheel includes four libraries:
>
> -rw-r--r--. 1 charris charris   273072 Jan  1  1980 libgcc_s.1.dylib
> -rwxr-xr-x. 1 charris charris  1550456 Jan  1  1980 libgfortran.3.dylib
> -rwxr-xr-x. 1 charris charris 63433364 Jan  1  1980
> libopenblasp-r0.3.5.dev.dylib
> -rwxr-xr-x. 1 charris charris   279932 Jan  1  1980 libquadmath.0.dylib
>
> I thought we only needed the openblas, but that in turn probably depends
> on libgcc. But why we have the fortran library and quadmath escapes me.
> Perhaps someone else knows.
>

I suspect it's a leftover from when we were using ATLAS, we did need a
Fortran runtime library at some point. The cause will be somewhere in the
numpy-wheel build scripts, there is a gfortran-install git submodule:
https://github.com/MacPython/numpy-wheels


>
> Note that compiling from source is different and will generally use
> different libraries. We don't use Accelerate because it is buggy, not
> thread safe, and it appears Apple is not interested in doing anything about
> that.
>
> Chuck
> _______________________________________________
> NumPy-Discussion mailing list
> NumPy-Discussion at python.org
> https://mail.python.org/mailman/listinfo/numpy-discussion
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/numpy-discussion/attachments/20190130/a028986a/attachment-0001.html>