I could be doing something wrong, but...

1. Alice starts `guix publich -u ambrevar`.
2. Bob, who did _not_ authorize Alice's  signing key:
   - herd stop guix-daemon
   - guix-daemon --build-users-grouop=guixbuild --substitute-urls='http://10.0.0.4:8080 https://ci.guix.gnu.org'
   - guix build curl

Result:

--8<---------------cut here---------------start------------->8---
downloading from http://10.0.0.4:8080/nar/gzip/...
--8<---------------cut here---------------end--------------->8---

Guix commit 8b00728144d0e4bbc740e1595c85f0ecee3f6fb0.

Am I missing something or there is something really wrong?

-- 
Pierre Neidhardt
https://ambrevar.xyz/