Provide PyQt-minimal and Qt-minimal as conda or pip packages

[smarie]

Goal : being able to install with something as simple as conda install PyQt5.6-minimal

I had to give up on this target for now because it is way too complicated to create such packages. The reason is different depending on the platform.

For windows platforms, two reasons:

• For an obscure reason I still cannot make the generated PyQt work with python 3.5 (3.6 works). The python interpreter crashes when doing from PyQt5 import QtCore
• Qt5.6.3-minimal needs to be on the system PATH. So if it is distributed as a conda package too, will it still be on the PATH ? There is most probably a way, since Qt5.9 is distributed that way.
• both libraries have a dependency with MSYS2/MINGW64, that requires users to install msys2+mingw64 and add it to the path anyway. This could be removed by compiling against msvc2015, see issue Create a windows version built against MSVC2015 #1 .

For linux platforms, the main reason for not being able to provide such packages is that PyQt5.6-minimal currently depends on Qt5.6.3-minimal according to an absolute file path location. I have not yet found how to replace this with the same kind of PATH-dependency happening on windows.

If anyone knows how anaconda did it for Qt5.9+PyQt5.9, I would be happy to follow the same procedure.

Finally one last thing is how to make sure that the resulting wheel/conda pkg will work on both 3.5, 3.6 and higher versions of python ? It seems to be the case in PyQt5.9 wheel but we see above that for the windows platform I dont manage to reproduce the behaviour.