It seems that the only thing that prevent building kdebase-libs without the accessibility USE flag is the line 96 in the kcapacitybar.cpp file. This line should be surrounded by the appropriate #ifdef/#endif code. I'm not fluent enough in portage and patches to submit a correct solution but it should be easier for a maintainer. And at least we should be able to build qt and kde without the whole accessibility code.
Which version? And how about to report this to upstream?
Version 4.8.3. Last time I tried to submit this upstream, I gave up. Too many hurdles...
> [ebuild UD ] kde-base/kdelibs-4.8.3::gentoo [9999::kde] USE="acl alsa bzip2 > fam handbook mmx nls opengl (policykit) semantic-desktop spell sse sse2 ssl > test udev udisks upower zeroconf -3dnow (-altivec) (-aqua) -debug -doc -jpeg2k > -kerberos -lzma -openexr (-upnp) (-udisks2%)" 11,923 kB Sorry we dont have such USE flag in kde-base/kdelibs.
The accessibility code is in the Qt librairies. All the x11-libs/qt-* modules force the accessibility USE flag, but it is ridiculous to compile all that code for just one line in the kcapacitybar.cpp file.