These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 0.82 s (backtrack: 0/20).


!!! All ebuilds that could satisfy "=dev-libs/9libs-1.0-r5" have been masked.
!!! One of the following masked packages is required to complete your request:
- dev-libs/9libs-1.0-r5::gentoo (masked by: PLAN9 license(s))
A copy of the 'PLAN9' license is located at '/Volumes/Disk 1/Repository/portage-git/licenses/PLAN9'.


For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.