Where to find backup recovery logs

We use the gitlab in docker, on the instructions in the crontab we make a backup, from which the script creates a hot copy on another server once a day.
In the case when the gitlab changes the version, the script does not work, it issues a message to the console:

GitLab version mismatch:
  Your current GitLab version (х.х.х) differs from the GitLab version in the backup!
  Please switch to the following version and try again:
  version: y.y.y

Question: where can I find this message in the log files?
This is necessary to monitor that the backup has not been restored.