I was pointed to this issue from the IRC channel. I am also experiencing similar "bad response" errors during `guix pull` and `guix upgrade`. Thanks to help from IRC, I was able to sort of work around the issue by simply brute-forcing the commands, running them over and over again until they completed successfully. 

Here are all the `guix pull` attempts it took: https://paste.debian.net/hidden/3dc48b23/

Here are the all the `guix upgrade` attempts after the pull finally completed: https://paste.debian.net/hidden/e453dd85/