gitlab preinstall: Upgrade failed. Retry the upgrade after upgrading your PostgreSQL version
We couldn’t upgrade our hosted GitLab to version 10.x as PostgreSQL was out of date. From version 8.15.x you could run
gitlab-ctl pg-upgrade so the only way around this was to upgrade to 9.5.x and then upgrade to the final version.
After taking a backup, we ran the following:
apt-get install gitlab-ce=9.5.9-ce.0