QWidget: Must construct a QApplication before a QWidget

Have you faced such error message? It's specially likely to appear if you are using Qt framework along with 3rd party libraries. The solution?

pkg_config and qmake

If you're developing an application with Qt which in turn relies on some library that uses the pkg-config tool, you can take advantage and simplify your Qt project file (.pro) as it will help avoiding hard-coded values for where to find headers and libraries for a particular package.

#inqlude: a list of Qt libraries

Do you ever wonder if a library alredy exist to assist you in a particular domain while devoloping an application with Qt? A little help from the friends at #inqlude may save you a lot of time while searching for such component.