The ebuild dev-util/kdevelop-4.3.90 of the kde overlay is missing the following runtime requirement: x11-libs/qt-declarative[qtwebkit] Such missing requirement prevents from opening the new "Learn kdevelop!" section of the welcome screen. I attach the fixed ebuild.
Created attachment 323616 [details] The fixed ebuild
Thanks for reporting. This is fixed in kde overlay now. http://git.overlays.gentoo.org/gitweb/?p=proj/kde.git;a=commit;h=d08d92512acde891f5ecfe1f07b5c684bf81c6b6