Trying to deploy Qt 5.6 on an rpi3

RobinChap

Hello all.
First time asking for help but I read a lot of post which unstuck me from many problems here so thanks about that.
So my current problem involves cross-compilation.
I came trough many errors and depedencies problems while trying to do this.
Even tho I was following : https://wiki.qt.io/RaspberryPi2EGLFS

Now I think I am good with it. QtBase is built. and every qt modules I use are built too.
My current problem being that I can't deploy on my rasp for the stupiddest reason a computer ever gave me: He is trying to upload files into "/home/robin/raspi/qt5pi/examples/multimediawidgets" instead of "/usr/local/qt5pi/examples/multimediawidgets" and I am not able to change that.

my target.path on my .pro is :

target.path = $$[QT_INSTALL_EXAMPLES]/multimediawidgets/STOREeBOX
INSTALLS += target

I am well aware that the problem is my qmake having his property "QT_INSTALL_EXAMPLES" set to "/home/robin/raspi/qt5pi/examples"
I tried to change it but it simply won't.
Example :

/robin@DebiaRobin:~/raspi/qt5/bin$ ./qmake -query "QT_INSTALL_EXAMPLES"
/home/robin/raspi/qt5pi/examples
robin@DebiaRobin:~/raspi/qt5/bin$ ./qmake -set "QT_VERSION" /usr/local/qt5pi/examples
robin@DebiaRobin:~/raspi/qt5/bin$ ./qmake -query "QT_INSTALL_EXAMPLES"
/home/robin/raspi/qt5pi/examples

If you are wondering why I'm trying to deploy into that specific spot well it is because for unknown reasons I can't compile anything involving Qtmultimediawidget if it's not from the example folder. Don't know why either.

I also tried to write the true path instead of using my qmake property and if I write anything else than what I have Qt says
"Project ERROR: /home/robin/raspi/qtbase/qtmultimedia/examples/multimediawidgets/STOREeBOX/STOREeBOX.pro installs target to unexpected location."

I searched everywere on the internet and I couldn't even find someone experiencing my problem so either it is really really uncommon either I am really missing some thing obvious.

Thanks to have read all of this.
I can add any more info you might need about this if needed.
Have a nice day.