during debuging with QtCreator I cannot browser my own source code. I build qt sources with the debug option and as you can see the filenames of the qt source code itself are visible and I can browse them with no problem. But somehow the CONFIG+=debug has no effect on my build.
build output:
Running build steps for project tcpconnector...
Starting: "/usr/local/Trolltech/Qt-4.7.4-DEBUG/bin/qmake" /home/user1/server/src-server/server.pro -r -spec linux-g++-64 CONFIG+=debug
The process "/usr/local/Trolltech/Qt-4.7.4-DEBUG/bin/qmake" exited normally.
Starting: "/usr/bin/make"
...
In the screenshot from the QtCreator debugger you can see that my own code Server::deleteDuplicateConnection is grayed out.

Like written in the comment. This just seemed to be a random phenomenon.