Oh … we have seen this before on major version upgrades of PG. @saj recently worked on something here.
The long story is that on some PG upgrades the DB collation changes underneath you and you due to libc changing stuff. You have no choice but to reindex.
What happened to you is that:
You did a major upgrade
Your index become somewhat corrupt
A second insert of a user for talk@remobjects.com was made - you now have a duplicate row despite the index disallowing it.
We touch the row and it highlights this issue cause it can not update an unrelated column
Fix is:
Find the user ids of the 2 users sharing the talk@remobjects.com email.
Either delete or rename the email on one of them
Proceed as planned
Do a full db reindex urgently to catch other issues
Your solution did solve it but the “upgrade” already passed (e no more updates); do I need to do anything special to rerun these migrations? I did ofc delete the dupe emails.