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

Calculating dependencies... done!

!!! All ebuilds that could satisfy "=net-misc/dahdi-2.4.0" have been masked.
!!! One of the following masked packages is required to complete your request:
- net-misc/dahdi-2.4.0 (masked by: EAPI 3)

The current version of portage supports EAPI '2'. You must upgrade to a
newer version of portage before EAPI masked packages can be installed.

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


 * IMPORTANT: 1 config files in '/etc' need updating.
 * See the CONFIGURATION FILES section of the emerge
 * man page to learn how to update config files.