Disabling the new "binfmt" doesn't work and breaks the build. I have
sent an email to the mailinglist and this might be fixed but at the
same time binfmt is split into a new package anyway. At the same time
we should enable some items we have now switched off. Once we start
to use/stabilize this build we need to check what we need and what the
cost is.
E.g. when using musl and trying to build the smallest possible
rootfs. Existing builds should not start to use these flags as
they would be likely to force a big rebuild.
While copying one build to a new directory we inherit most of
the config but it is better to collect this in a single place
so external contributors build with the same options we use.