@sunneyxue, can you share the output of the following?
$ apt policy systemd $ sudo systemctl daemon-reload $ sudo systemctl enable somethingthatdefinitelydoesnotexist.service $ sudo apt update
@sunneyxue, can you share the output of the following?
$ apt policy systemd finitelydoesnot exist.service
$ sudo systemctl daemon-reload
$ sudo systemctl enable somethingthatde
$ sudo apt update