The following program fails to compile:

#include <QtGui/QBrush>
#include <QtCore/QDebug>

int main(int argc, char *argv[])
{
QBrush b;
qDebug() << b << b.texture();
}

The error is:

test.cpp: In function 'int main(int, char**)':
test.cpp:7:32: error: ambiguous overload for 'operator<<' in 'operator<<(QDebug, const QBrush&)(((const QBrush)(& b))) << QBrush::texture() const()'
test.cpp:7:32: note: candidates are:
/local/Qt4/qt-4.8/include/QtGui/qbrush.h:171:21: note: QDebug operator<<(QDebug, const QBrush&)
/local/Qt4/qt-4.8/include/QtCore/qvariant.h:606:22: note: QDebug operator<<(QDebug, const QVariant&)

This is a regression in Qt 4.8 branch. Not sure if the bug is in QDataStream or in QBrush, please reassign if required.