Qt related

Kdevelop: rebuild doesn't run qmake!! If build options have changed, re-run qmake for changes in .pro files to take effect!!!

When creating new basic qt4 kdevelop project, GUI support is not configured (relative paths to the qt include files that are not QtCore, as well as other libraries than QtCore). Add those yourself, or choose Qt4 application (not the basic one)

Mandriva

Adapt compiler flags in qmake projects in file /usr/local/Trolltech/Qt-4.2.3/mkspecs/linux-cxx/qmake.conf

(K)Ubuntu

Similar, but /usr/local/Trolltech/Qt-4.2.3/ is replaced by /usr/share/qt4/

Install qt4-dev-tools