A lot of ebuilds depend on alsa-driver. 2.6 has the alsa drivers in the main tree. It should be possible to disable alsa-driver dependencies without setting -alsa, as -alsa would compile packages without alsa support. Possibly +kernel2.6 ? Reproducible: Always Steps to Reproduce: 1. Install gentoo, with kernel 2.6 2. Compile alsa drivers in your kernel 3. Set USE="alsa" in make.conf 4. emerge -pv kde 5. Notice it wants to merge alsa-drivers, which we already have Actual Results: Alsa drivers tried to merge Expected Results: Not merge alsa-driver, since I only compiled the one for my sound card and it's pointless to merge the alsa-driver ebuild. Merging all of the alsa drivers in when the one I need already exists is both redundant and excessive.
things should depend on virtual/alsa which 2.6 provides, you should file bugs against packages that don't do this