Precompiled header using QtGui master header stops working on Mac

Reproducible with the following project:

echo "CONFIG += precompile_header" > test.pro
echo "PRECOMPILED_HEADER = foo.h" >> test.pro
echo "SOURCES += foo.cpp" >> test.pro
echo "#include <QtGui>" > foo.h
touch foo.cpp
qmake
make

/usr/local/Trolltech/Qt-4.3.0/include/QtGui/qaccessible.h: In static member function 'static int QMetaTypeId<QSet<QAccessible::Method> >::qt_metatype_id()':
/usr/local/Trolltech/Qt-4.3.0/include/QtGui/qaccessible.h:297: error: expected unqualified-id before '=' token
<snip>