>>   ./pre-inst-env guix system image -t iso9660 --label=Guix \
>>     gnu/system/install.scm
>
> Additionally, I had to do “GUIX_ALLOW_ME_TO_USE_PRIVATE_COMMIT=y
> make update-guix-package”.  Or else the installer was using a Guix that
> did not have the lines swapped.

Hmm this is surprising because we’re already using (current-guix) in
(gnu installer).

> Also before I did the GPG authorization dance (my x86 machine isn’t
> worth getting my actual commiter GPG keys, so I make sure its dummy GPG
> key is in the keyring branch, .guix-authorizations file, that
> guix/channels.scm’s default guix channel points to the url
> /home/florian/src/guix and to the commit with the new authorization).
> Then I guix pulled.  So that building the installer succeeds.  I did
> *not* use ./pre-inst-env.

Ah yes, apologies.  You should be able to disable authentication with
this: