Can't compile on Fedora 29 even with opencv2 and ocl included with -I

[Poikilos]

OpenCV is on 3.4.1 on Fedora, so I tried the last 2.x tarball of opencv. OpenCV builds successfully, but butterflow does not:

• installing opencl-devel doesn't do any good (reason why is that ocl.hpp is drastically different in v3 according to https://stackoverflow.com/questions/34422276/opencv-3-0-error-include-ocl-hpp)

  
  sudo dnf -y install git python2-setuptools python2-virtualenv python2-numpy ocl-icd opencl-headers ffmpeg

mkdir -p ~/Downloads/git/ cd ~/Downloads/git/ wget https://github.com/opencv/opencv/archive/2.4.13.6.tar.gz tar xf 2.4.13.6.tar.gz

but it still doesn't have ocl (except in modules dir) so:

cd $USER/Downloads/git/opencv-2.4.13.6 mkdir build cd build

add -DOPENCV_GENERATE_PKGCONFIG=ON for "projects that use OpenCV" "not using CMake" (see https://docs.opencv.org/trunk/d7/d9f/tutorial_linux_install.html)

building opencv2 works, but may not be necessary:

cmake -D CMAKE_BUILD_TYPE=Release -DOPENCV_GENERATE_PKGCONFIG=ON -D CMAKE_INSTALL_PREFIX=/usr/local .. make -j$(nproc)

sudo make install # I didn't try installing opencv2

export CPPFLAGS="-I$HOME/Downloads/git/opencv-2.4.13.6/include -I$HOME/Downloads/git/opencv-2.4.13.6/modules/ocl/include" pip2 install https://github.com/dthpham/butterflow/archive/master.zip

Result with `export CPPFLAGS="-I/usr/include/ffmpeg -I$HOME/Downloads/git/opencv-2.4.13.6/include -I$HOME/Downloads/git/opencv-2.4.13.6/modules/ocl/include"`:
https://pastebin.com/pF1tdEkB
(I tried to remove `-I/usr/include/ffmpeg` from CPPFLAGS [to avoid later version of h* files] but still got:
https://pastebin.com/6nEBG3qd
--that file [libavcodec/avcodec.h] is in ffmpeg, and including ffmpeg with -I makes the first pastebin error)