Occasionally I get an error like this. It happens for both the system profile and my user profile, the "/root" part just changes to "/brad" when it's to my user. My fix has been to delete the file and run pull again, which works, but clearly isn't a permanent fix if the error comes back later. I wonder if the migration message is a hint. Is it supposed to be migrating stuff every time? I will hold off on deleting the file for now so that I can try any suggestions for solving it properly. I just tried to do the same as my user and didn't get the error, so maybe deleting it from one affects the other. Not sure.
address@hidden:~/ > sudo -E guix pull
Migrating profile generations to '/var/guix/profiles/per-user/root'...
guix pull: error: symlink: File exists: "/var/guix/profiles/per-user/root/current-guix"
my guix version: guix (GNU Guix) b634b5c253cb3351eb074c64be838f72aa83f54d