Qtcreator : Problem to compile examples

I installed qtcreator 1.2.1 by downloaded it from the website.

qtdemo works. I can compile my program but the examples doesn't compile :

Code:

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Running build steps for project tabdialog...
Starting: /usr/bin/qmake-qt4 /usr/lib/qt4/examples/dialogs/tabdialog/tabdialog.pro -spec /usr/share/qt4/mkspecs/linux-g++ -r CONFIG+=debug 
Failure to open file: /usr/lib/qt4/examples/dialogs/tabdialog/Makefile
Unable to generate makefile for: /usr/lib/qt4/examples/dialogs/tabdialog/tabdialog.pro
Exited with code 5.
Error while building project tabdialog
When executing build step 'QMake'

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I install qt from ubuntu package... I tried with the package qt creator 1.0.0 it was the same.

Go to the project settings pane and check the shadow build option - you have to point a directory you have the read-write access to.

Great that work!!
Thank