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

Calculating dependencies ... done!
Dependency resolution took 0.89 s (backtrack: 0/20).


The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by media-plugins/vdr-serial-0.0.6a-r3::gentoo
# required by =media-plugins/vdr-serial-0.0.6a-r3 (argument)
>=acct-user/vdr-0-r3 serial

 * In order to avoid wasting time, backtracking has terminated early
 * due to the above autounmask change(s). The --autounmask-backtrack=y
 * option can be used to force further backtracking, but there is no
 * guarantee that it will produce a solution.

!!! All ebuilds that could satisfy "media-fonts/corefonts" have been masked.
!!! One of the following masked packages is required to complete your request:
- media-fonts/corefonts-1-r7::gentoo (masked by: MSttfEULA license(s))
A copy of the 'MSttfEULA' license is located at '/Volumes/Disk 1/Repository/portage-git/licenses/MSttfEULA'.


(dependency required by "media-video/vdr-2.8.2::gentoo" [ebuild])
(dependency required by "media-plugins/vdr-serial-0.0.6a-r3::gentoo" [ebuild])
(dependency required by "=media-plugins/vdr-serial-0.0.6a-r3" [argument])
For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.