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 "=media-libs/libopenaptx-9999" have been masked.
!!! One of the following masked packages is required to complete your request:
- media-libs/libopenaptx-9999::gentoo (masked by: package.mask, missing keyword)
/Volumes/Disk 1/Repository/portage-git/profiles/package.mask:
# Michał Górny <mgorny@gentoo.org> (2021-07-06)
# Upstream changed license to GPL-3+ in order to deliberately cause
# incompatiblity with revdep licenses.  Mask until the situation
# is resolved.  Bug #791259.


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