# emerge -avC qt

>>> These are the packages that would be unmerged:

 x11-libs/qt
    selected: 3.3.8-r4 4.3.3
   protected: none
     omitted: none

>>> 'Selected' packages are slated for removal.
>>> 'Protected' and 'omitted' packages will not be removed.

Would you like to unmerge these packages? [Yes/No] n

Quitting.

cerval ~ # emerge -avC >qt-4.3.3
cerval ~ # emerge -avC >qt-4.3.3
cerval ~ # emerge -avC >=qt-4.3.3
cerval ~ # emerge -avC >qt-4.3.3
cerval ~ # emerge -avC >qt-4.3.3