f90wrap on Windows (Python wrapper for Fortran 90)

Question

I've got a Python program that calls Fortran routines. These Fortran routines are wrapped with f90wrap (https://github.com/jameskermode/f90wrap), and I've verified that the setup works correctly on Linux and Mac OSX. I'm now trying to get the setup to work equally well on Windows (because I collaborate with people who cannot sometimes switch to Linux).

I've got gfortran working through a MinGW installation and verified that Fortran programs compile and run without errors. I've also verified that a Python 2.7 installation works without issues, and was able to use pip to add numpy, matplotlib and scipy modules without issues. Both MinGW and Python are 64-bit, running on Windows 10. I've also got CMake to create Makefiles that compile standalone fortran programs using mingw-make, so the only part left (to get things working on Windows) is to make sure the Python wrapper for Fortran-90 works. That's where I ran into some issues.

I'm running mingw-make in Powershell (which executes in cmd.exe, I believe).

Q1: The pip installation for f90wrap failed with an absolute path/relative path error (https://github.com/jameskermode/f90wrap/issues/73)

A1: I downloaded the source and ran "python setup.py install", and that got stuck as well. I ran into a "multiple_definition" error with Windows 10, Python 2.7 and mingw-w64.

F:/Programs/mingw/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.2.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-atonexit.o):atonexit.c:(.text+0xc0): multiple definition of atexit' F:\Programs\Python\libs/libmsvcr90.a(deoks01081.o):(.text+0x0): first defined here F:/Programs/mingw/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.2.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-mingw_helpers.o):mingw_helpers.c:(.text+0x0): multiple definition of_decode_pointer' F:\Programs\Python\libs/libmsvcr90.a(deoks00231.o):(.text+0x0): first defined here F:/Programs/mingw/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/7.2.0/../../../../x86_64-w64-mingw32/lib/../lib/libmingw32.a(lib64_libmingw32_a-mingw_helpers.o):mingw_helpers.c:(.text+0x10): multiple definition of `_encode_pointer' F:\Programs\Python\libs/libmsvcr90.a(deoks00241.o):(.text+0x0): first defined here collect2.exe: error: ld returned 1 exit status error: Command "gcc -g -shared build\temp.win-amd64-2.7\Release\f90wrap\arraydatamodule.o build\temp.win-amd64-2.7\Release\programs\python\lib\site-packages\numpy\f2py\src\fortranobject.o -LF:\Programs\Python\libs -LF:\Programs\Python\PCbuild\amd64 -lpython27 -lmsvcr90 -o build\lib.win-amd64-2.7\f90wrap\arraydata.pyd" failed with exit status 1

Answer 1

I got f90wrap to work on Windows 10 (64 bit, home edition) with Anaconda Python 3.8.8, numpy version 1.20.1 and f90wrap 0.2.7; gfortran through mingw-w64 (v8.1.0). I built f90wrap with python setup.py install after telling distutils.cfg to use mingw32 (and not the microsoft visual c/c++ compiler)

Links:

1. https://sourceforge.net/projects/mingw-w64/files/Toolchains%20targetting%20Win32/Personal%20Builds/mingw-builds/installer/mingw-w64-install.exe/download
2.