localhost shelly # layman -s sabayon
* Running command "/usr/bin/svn update "/usr/portage/local/layman/sabayon""...
At revision 1976.
*
* Success:
* ------
*
* Successfully synchronized overlay "sabayon".
localhost shelly # emerge genkernel sabayon-sources
Calculating dependencies... done!
[ebuild     U ] sys-kernel/genkernel-3.4.10_pre2 [3.4.9_pre11-r3]
[ebuild  N    ] sys-kernel/sabayon-sources-2.6.23-r1  USE="symlink -build"
[blocks B     ] =sys-kernel/sabayon-sources-2.6.23-r1 (is blocking sys-kernel/linux-sabayon-2.6.23-r1)

 * Error: The above package list contains packages which cannot be
 * installed at the same time on the same system.

For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):

http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked

localhost shelly # eselect kernel list #note which you want to install.  it has a number like this next to it [x] more than likely, x = 2 [2]
Available kernel symlink targets:
  (none found)
localhost shelly # eselect kernel list
Available kernel symlink targets:
  (none found)
localhost shelly # eselect kernel set x
!!! Error: Target "x" doesn't appear to be valid!
Killed
localhost shelly # eselect kernel set 2
!!! Error: Target "2" doesn't appear to be valid!
Killed
localhost shelly #