mingw32-g++.exe -LC:\wxWidgets-2.8.6\include
You need to fix this it should be a path to the Library.
I would guess it should be "mingw32-g++.exe -LC:\wxWidgets-2.8.6\lib\gcc_lib"
What compiler are you trying to use? MinGW GCC or Microsoft Visual C++?
( The log above showing includes of Microsoft Visual C++ folders which will cause issues.)
Tim S