QVariantAnimation instantiation runtime crash; symbol lookup error: undefined symbol

I'm getting this weird runtime crash when instantiating QVariantAnimation or QPropertyAnimation. It appears this happens when the program doesn't link appropriately the class. But I have double checked my simple project and can't see anything wrong.

Code:

---

#include <QtCore/QVariantAnimation>
#include <QtCore/QEasingCurve>
 
class MyAnimacion : public QVariantAnimation {
public:
	MyAnimacion() : QVariantAnimation()	{}
	~MyAnimacion(){}
	void updateCurrentValue( const QVariant & value ) {}
};
int main() {
	MyAnimacion myAnimacion;
	return 0;
}

---

In Eclipse:
Qt Include Directory: /home/user/DEV/SDK/QtSDK/qt/include
Qt Link Directory: /home/user/DEV/SDK/QtSDK/qt/lib
Link Library: QtCore

Code:

---

make all 
Building file: ../src/AnimationTest.cpp
Invoking: GCC C++ Compiler
g++ -I/home/user/DEV/SDK/QtSDK/qt/include -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/AnimationTest.d" -MT"src/AnimationTest.d" -o"src/AnimationTest.o" "../src/AnimationTest.cpp"
Finished building: ../src/AnimationTest.cpp
 
Building target: AnimationTest
Invoking: GCC C++ Linker
g++ -L/home/user/DEV/SDK/QtSDK/qt/lib -o"AnimationTest"  ./src/AnimationTest.o   -lQtCore
Finished building target: AnimationTest

---

Runtime Crash:

Code:

---

../AnimationTest: symbol lookup error: ../AnimationTest: undefined symbol: _ZN17QVariantAnimationC2EP7QObject

---

I don't know if QVariantAnimation is restricted to QtGui, I'm trying to use it to manually update the position of stuff in my game with the keyValueAt method.

Ok. I figured out that if I create a QT Console project with Eclipse's QT plugin, this crash does not happen. So, there must be something missing in my c++ project configuration.

The strange thing is that this is not the first qt class I use in my current project. I was using a lot of QtCore classes and QtXml previous to this problem, and everything compiled, linked and worked. But for some reason this QVariantAnimation is crashing...

The only difference I can see is that "Qt projects" have this .pro file that normal C++ projects don't have. But I don't see anything special from it apart from specifying the code structure and used qt libs.

Thanks for any hint.