I’m guessing this is the same as "https://discuss.circleci.com/t/postgresql-always-reports-job-was-canceled/29208." After the entire build is done processing, it probably leads to these messages in the bottom of the container.
I don’t really agree with the comment there saying "
Job was canceled means that we canceled that background step after the job was complete. It’s normal and not a cause for concern." It’s a false alarm causing us to be concerned.