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 "=sys-kernel/linux-firmware-99999999" have been masked.
!!! One of the following masked packages is required to complete your request:
- sys-kernel/linux-firmware-99999999::gentoo (masked by: || ( ) linux-fw-redistributable license(s), missing keyword)
A copy of the 'linux-fw-redistributable' license is located at '/Volumes/Disk 1/Repository/portage-git/licenses/linux-fw-redistributable'.


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