butters ~ # emerge -v kde
Calculating dependencies... done!

>>> Emerging (1 of 9) kde-base/kdenetwork-3.5.2 to /
 * kdenetwork-3.5.2.tar.bz2 MD5 ;-) ...                                                                                                  [ ok ] * kdenetwork-3.5.2.tar.bz2 RMD160 ;-) ...                                                                                               [ ok ] * kdenetwork-3.5.2.tar.bz2 SHA1 ;-) ...                                                                                                 [ ok ] * kdenetwork-3.5.2.tar.bz2 SHA256 ;-) ...                                                                                               [ ok ] * kdenetwork-3.5.2.tar.bz2 size ;-) ...                                                                                                 [ ok ] * checking ebuild checksums ;-) ...                                                                                                     [ ok ] * checking auxfile checksums ;-) ...                                                                                                    [ ok ] * checking miscfile checksums ;-) ...                                                                                                   [ ok ] * checking kdenetwork-3.5.2.tar.bz2 ;-) ...                                                                                             [ ok ]QA Notice: USE Flag 'kernel_linux' not in IUSE for kde-base/kdenetwork-3.5.2
 * To support Video4Linux webcams in this package is required to have
 * =x11-libs/qt-3* compiled with OpenGL support.
 * Please reemerge =x11-libs/qt-3* with USE="opengl".

!!! ERROR: kde-base/kdenetwork-3.5.2 failed.
Call stack:
  ebuild.sh, line 1562:   Called dyn_setup
  ebuild.sh, line 665:   Called pkg_setup
  kdenetwork-3.5.2.ebuild, line 55:   Called die

!!! Please reemerge =x11-libs/qt-3* with USE="opengl".
!!! If you need support, post the topmost build error, and the call stack if relevant.