When compiling, cmake failed during the linking process.
undefined reference to `vtable for MainWindow'
Simply add the following line to the mainwindow.cpp:
Also add this line to your CMakeLists.txt near the top:
include (KDE4Defaults)
I don't exactly know why this happens to me, but I suspect the fact that I have not built any special environment for working on KDE4 applications (as described here.
Can someone who understands the process please add the appropriate steps to the main tutorial?