Following the update from SMG 10.6.6. to 10.7.x, the messages log shows a number of "fatal" log events but the update otherwise appears to complete and the system runs without issue.
2020 May 28 10:40:53 (warning) kernel: [65783.426319] <27>systemd-tmpfiles[10940]: Failed to fstat() file /var: Invalid argument 2020 May 28 10:40:53 (warning) kernel: [65783.426342] <27>systemd-tmpfiles[10940]: Failed to fstat() file /var/run/sepermit: Invalid argument 2020 May 28 10:40:53 (warning) kernel: [65783.426380] <27>systemd-tmpfiles[10940]: Failed to fstat() file /run/lock: Invalid argument
These log messages are an expected by product of the in place migration of underlying operating system.
These messages may be safely ignored.