The following message was displayed when I attempted to emerge kde-base/kdesupport (BTW, other KDE packages built fine). The version of QT I have installed on my yesterday built system is 2.3.1. checking for Qt... configure: error: Qt (>= Qt 2.2.2) (libraries) not found. Please check your installation! For more details about this problem, look at the end of config.log. !!! ERROR: The ebuild did not complete successfully. !!! Function src_compile, Line 3, Exitcode 1 !!! (no error message) !!! emerge aborting on /usr/portage/kde-base/kdesupport/kdesupport-2.1-r1.ebuild .
You can't and shouldn't build kdesupport. It is a part of kde 2.1, not 2.2. It exists for backward compatibility only.