Qt5 ignores fontconfig

I build a test app using next source codes:

#include <QApplication>
#include <QLabel>

int main(int argc, char **argv) {
	QApplication app(argc, argv);
	QLabel label;
	label.setText("Test Font");
	label.adjustSize();
	label.show();
	return app.exec();
}

with Qt 4.8.4(distro package) and Qt 5.0.1(both of custom build and official prebuild package from qt-project.org). The results are attatched.
Each font of test-qt4 and test-qt5 is definetly different, and hinting option is also different.
I think this is because font rendering of test-qt5 is not applied fontconfig.(the font of test-qt4 follows fontconfig correctly)

It can be confirmed by ldd. The linked libraries of test-qt4 list contain libfontconfig:

1. ldd test-qt4 | grep libfontconfig
   libfontconfig.so.1 => /usr/lib/libfontconfig.so.1 (0x00007f2e3acab000)
   , but those of test-qt5 don't('ldd test-qt5 | grep libfontconfig' shows nothig).
   Of couse, Qt5 is built with support of fontconfig with -fontconfig option for configure and I double-checked it:
   #grep FontConfig config.summary
   FontConfig support ..... yes

I deeply hope Qt5 handles fontconfig well.