First of all i want to thank you guys for answering my questions.
Again the answer was simple.
Don't use the qmake that you obtain after the configure (the one in the build directory).
But use the one which is in your sysroot directory (probably in sysroot/usr/lib/qt/bin )
I have been starting development using QT a few weeks ago and encountered a similar problem. Everything was fine, compiling the apps and deploying to the PI using QT Creator without issues. But as soon as I started the app (or wanted to debug) the app died with a Segfault.
After some hours, I noticed that libts on Jessie has been quite old. I re-installed Jessie-Lite and compiled libts on my own, directly from the GitHub repository here: lbts GitHub Repo .
Afterwards I simply followed the tutorial to cross-compile QT5 like documented in this tutorial: RaspberryPi2EGLFS
Basically I followed each step within the tutorial and the only thing I did not do, was to install any libts related packages (just check the apt-get install commands in the tutorial and don't install the libts related packages).
I know, the thread is quite old, but maybe someone will look it up.
@Ajith_P_V Yes that is right, you don't need to add the physical device. That was really just an extra option in case that was convenient to you later on : )
Have a look at creating kits for cross compiling in the qt docs if you can find it! - there are quite a few bits of info out there that may fill in the gaps I have left. I only gave the general steps required.