Cannot build Python module - Windows 10 (64bit) i686-w64-mingw32 Python39

[mcluskyism]

Hello, first of all forgive my English. Probably I am unable to understand the readme. I would build the Python module. Tried first with Visual Studio 2019, then with the oldest mingw at 32bit, then with the newest mingw, 64bit first, now my latest attemp with newest i686-w64-mingw32 so I suppose it is 32bit. Every attempt I get different compiler errors. The latest one while trying to execute python setup.py build I get: fir.cc: In destructor 'HalfRateFirFilter::~HalfRateFirFilter()': fir.cc:91:10: warning: deleting object of abstract class type 'FirFilter<float, float>' which has non-virtual destructor will cause undefined behaviour [-Wdelete-non-virtual-dtor] delete f0; fir.cc:92:10: warning: deleting object of abstract class type 'FirFilter<float, float>' which has non-virtual destructor will cause undefined behaviour [-Wdelete-non-virtual-dtor] delete f1; fir.cc:93:10: warning: deleting object of abstract class type 'FirFilter<float, float>' which has non-virtual destructor will cause undefined behaviour [-Wdelete-non-virtual-dtor] delete f2; error: command 'C:\MinGW_w64\bin\gcc.exe' failed with exit code 1. I suppose the relevant part is in fir.cc between lines 58 to 94. What I am doing totally wrong? Thank you