Cannot compile with Ubuntu 20.04, OpenCV 4.2.0 and Python 3.8.0

[Mechazo11]

Hi @solivr,

Have you had a chance to test the compilation of the cython wrapper with Ubuntu 20.04? Following your instructions, I tried to compile it but it fails.

Here is the console output

icore_base@icore-nitro5:~/Documents/semantic_single_agent/cython_lib/cython_opencvMat$ python3 setup.py build_ext --inplace
running build_ext
x86_64-linux-gnu-gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -g -fwrapv -O2 -fPIC -I/home/icore_base/.local/lib/python3.8/site-packages/numpy/core/include -I/usr/local/include -I/usr/include/python3.8 -c opencv_mat.cpp -o build/temp.linux-x86_64-3.8/opencv_mat.o
In file included from /home/icore_base/.local/lib/python3.8/site-packages/numpy/core/include/numpy/ndarraytypes.h:1960,
                 from /home/icore_base/.local/lib/python3.8/site-packages/numpy/core/include/numpy/ndarrayobject.h:12,
                 from /home/icore_base/.local/lib/python3.8/site-packages/numpy/core/include/numpy/arrayobject.h:5,
                 from opencv_mat.cpp:642:
/home/icore_base/.local/lib/python3.8/site-packages/numpy/core/include/numpy/npy_1_7_deprecated_api.h:17:2: warning: #warning "Using deprecated NumPy API, disable it with " "#define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION" [-Wcpp]
   17 | #warning "Using deprecated NumPy API, disable it with " \
      |  ^~~~~~~
opencv_mat.cpp:650:10: fatal error: core/core.hpp: No such file or directory
  650 | #include "core/core.hpp"
      |          ^~~~~~~~~~~~~~~
compilation terminated.
error: command '/usr/bin/x86_64-linux-gnu-gcc' failed with exit code 1

Any help in solving the compilation issue will be highly appreciated.