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

Calculating dependencies ... done!
Dependency resolution took 0.83 s (backtrack: 0/20).


!!! All ebuilds that could satisfy "=games-server/mtavc-0.5-r2" have been masked.
!!! One of the following masked packages is required to complete your request:
- games-server/mtavc-0.5-r2::gentoo (masked by: MTA-0.5 license(s), missing keyword)
A copy of the 'MTA-0.5' license is located at '/Volumes/Disk 1/Repository/portage-git/licenses/MTA-0.5'.


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