[root@ip-192-168-1-153:~]# nixos-rebuild switch --show-trace --upgrade
warning: unknown setting 'allowed-uris'
unpacking channels...
created 7 symlinks in user environment
building Nix...
warning: unknown setting 'allowed-uris'
building the system configuration...
updating GRUB 2 menu...
activating the configuration...
warning: not applying GID change of group ‘hydra’ (499 -> 122)
warning: not applying UID change of user ‘hydra’ (1000 -> 122)
warning: not applying UID change of user ‘hydra-queue-runner’ (1001 -> 235)
warning: not applying UID change of user ‘hydra-www’ (1002 -> 236)
setting up /etc...
reloading user units for kreisys...
setting up tmpfiles