[gentoo-user] trying to upgrade some old, never upgraded image for an embedded system …

[Thomas Schweikle]

trying to upgrade some old, never upgraded image for an embedded system I
ran into a problem I do not have a solution for:

!!! All ebuilds that could satisfy
">=dev-lang/python-exec-2:=[python_targets_pypy(-)?,python_targets_python2_7(-)?,python_targets_python3_5(-)?,python_targets_python3_6(-)?,python_targets_python3_7(-)?,python_targets_python3_8(-)?,-python_single_target_pypy(-),-python_single_target_python2_7(-),-python_single_target_python3_5(-),-python_single_target_python3_6(-),-python_single_target_python3_7(-),-python_single_target_python3_8(-)]"
have been masked.
!!! One of the following masked packages is required to complete your
request:
- dev-lang/python-exec-9999::gentoo (masked by: EAPI 7)
- dev-lang/python-exec-2.4.6-r1::gentoo (masked by: EAPI 7)

The current version of portage supports EAPI '6'. You must upgrade to a
newer version of portage before EAPI masked packages can be installed.
(dependency required by "sys-apps/portage-2.3.79::gentoo" [ebuild])
(dependency required by "portage" [argument])
For more information, see the MASKED PACKAGES section in the emerge
man page or refer to the Gentoo Handbook.

Trying to unmask the given packages just does not help – it keeps telling
me about eapi versions not matching.

Searching the internet did not give any hints other than such not working.
Any idea?

I've tried:
emerge --sync
emerge -qav python
emerge -qav sys-kernel/gentoo-sources
emerge -qav sys-kernel/git-sources
emerge -qav sys-kernel/vanilla-sources
emerge -qav sys-kernel/genkernel
USE='-rsync-verify' emerge -qavO portage
emerge -qavN portage <- fails
emerge -qavuND @world <- fails too.

Or shall I consider gentoo unupgradeable after anyone changed eapi versions?

-- 
Thomas