It seems that we are facing problems with Postgres 9.6.8, just released:

https://www.postgresql.org/docs/9.6/static/release-9-6-8.html

And all docker and CI runs have started to fail. So we have proceed to pin PG to 9.6.7:

• docker in general: https://github.com/moodlehq/moodle-docker/pull/77
• ci runs in particular too.

And also have created https://github.com/moodlehq/moodle-docker/issues/78 to proceed to unpin once we know it's safe to do so. That implies discovering what's wrong with the new version of postgres. It maybe Moodle, it maybe Postgres, it maybe docker containers...

This issue is about discover which is the problem, fix it if possible and signal both moodle-docker and ci to unpin pg (revert the pin).

Ciao