I've been facing the same issue, not a fresh install in my case.

I'm not sure what the  problem is, but forcing bordeaux.guix.gnu.org as the substitute server to use got me past the issue. 

> guix pull --substitute-url="https://bordeaux.guix.gnu.org"

This link was also helpful and mentions the same error with same backtrace: https://simon.tournier.info/posts/2023-06-23-hackathon-repro.html