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

Calculating dependencies ... done!
Dependency resolution took 0.93 s (backtrack: 0/20).


!!! All ebuilds that could satisfy "=sys-firmware/nvidia-firmware-340.32-r1" have been masked.
!!! One of the following masked packages is required to complete your request:
- sys-firmware/nvidia-firmware-340.32-r1::gentoo (masked by: NVIDIA-r2 license(s))
A copy of the 'NVIDIA-r2' license is located at '/Volumes/Disk 1/Repository/portage-git/licenses/NVIDIA-r2'.


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