Alright, I guess the *real* issue is in which version of the `guix` command is being used. I had just installed this instance of Guix using the installer script, so the version used for the initial pull (`/usr/local/bin/guix`) was still `hash`ed. Maybe another logout would have solved my issue, but is was able to get around it by `hash`ing `~/.config/guix/current/bin/guix`.

jpoiret helped me through this on the IRC: https://logs.guix.gnu.org/guix/2023-06-05.log#164216