> sudo nixos-rebuild switch
building Nix...
building the system configuration...
activating the configuration...
setting up /etc...
reloading user units for sddm...
reloading user units for baldr...
setting up tmpfiles
warning: the following units failed: systemd-timesyncd.service

● systemd-timesyncd.service - Network Time Synchronization
   Loaded: loaded (/nix/store/sh3a8j39frr2csmhf4yvr9frlyj0dnc2-systemd-243.3/example/systemd/system/systemd-timesyncd.service; enabled; vendor preset: enabled)
  Drop-In: /nix/store/q4lsy9c6bqsvvzrn8qgjafz0dqjap5qk-system-units/systemd-timesyncd.service.d
           └─overrides.conf
   Active: failed (Result: exit-code) since Sun 2020-02-23 15:26:13 CET; 35ms ago
     Docs: man:systemd-timesyncd.service(8)
  Process: 4475 ExecStart=/nix/store/sh3a8j39frr2csmhf4yvr9frlyj0dnc2-systemd-243.3/lib/systemd/systemd-timesyncd (code=exited, status=238/STATE_DIRECTORY)
 Main PID: 4475 (code=exited, status=238/STATE_DIRECTORY)
       IP: 0B in, 0B out
      CPU: 817us

Feb 23 15:26:13 baldr systemd[1]: systemd-timesyncd.service: Service has no hold-off time (RestartSec=0), scheduling restart.
Feb 23 15:26:13 baldr systemd[1]: systemd-timesyncd.service: Scheduled restart job, restart counter is at 5.
Feb 23 15:26:13 baldr systemd[1]: Stopped Network Time Synchronization.
Feb 23 15:26:13 baldr systemd[1]: systemd-timesyncd.service: Start request repeated too quickly.
Feb 23 15:26:13 baldr systemd[1]: systemd-timesyncd.service: Failed with result 'exit-code'.
Feb 23 15:26:13 baldr systemd[1]: Failed to start Network Time Synchronization.
warning: error(s) occurred while switching to the new configuration