Hi, guix publish speaking. Welcome!
Here is the signing key for this server.
curl -fLO https://guix.fish.foo/signing-key.pub
curl -fLO https://guix.fish.foo/signing-key.pub.asc
The OpenPGP key for this signature is published in bitcoin-core/guix.sigs as builder-keys/willcl-ark.gpg.
curl -fL https://raw.githubusercontent.com/bitcoin-core/guix.sigs/refs/heads/main/builder-keys/willcl-ark.gpg -o willcl-ark.gpg
gpg --import willcl-ark.gpg
gpg --verify signing-key.pub.asc signing-key.pub
Either authorize the Guix signing key as root:
guix archive --authorize < signing-key.pub
Or, with sudo:
sudo guix archive --authorize < signing-key.pub
For bitcoin build scripts under ./contrib/guix, set SUBSTITUTE_URLS:
export SUBSTITUTE_URLS='https://guix.fish.foo https://ci.guix.gnu.org'
To make this more permanent you can change the default list of substitute servers by starting guix-daemon with --substitute-urls. You will likely need to edit your init script:
guix-daemon <cmd> --substitute-urls='https://guix.fish.foo https://ci.guix.gnu.org'
Or override the default list for one guix invocation:
guix <cmd> --substitute-urls='https://guix.fish.foo https://ci.guix.gnu.org'