qt4-corelib won't build

[fmw]

Hi,

in a current attempt to update most everything, I'm hitting a wall with devel/qt4-corelib.

Animation::registerInterpolator(QVariant (*)(const void*, const void*, qreal), int)':
animation/qvariantanimation.cpp:441: error: 'QMutexPool' has not been declared
animation/qvariantanimation.cpp: In static member function 'static QVariant (* QVariantAnimationPrivate::getInterpolator(int))(const void*, const void*, qreal)':
animation/qvariantanimation.cpp:459: error: 'QMutexPool' has not been declared
*** Error code 1

System is 8.4-RELEASE.

Any ideas?