Issue in wrapping a minimal custom QMainWindow

This GitHub repo has a minimal example that describes the issue.

The CMakelists.txt is based on the `scriptableapplication` in the 5.9 branch for the shiboken settings.

The code generation triggers a lot of warnings that are listed here. At compilation, this error occurs.

Finally, I believe that the addition of a simple CMake-based `foopy` example to the project would be very helpful to newbies (since the `scriptableapplication` example does a bit more than just binding a class).