Fider prevents postgres major upgrade with pg_upgrade

[dani]

When we have a fider database on a postgres cluster, it prevents upgrading from one major version to another (in my case, trying to upgrade from 17 to 18). the checks find

2025-12-15 19:54:13.930 Upgrading PG data from /data/db//17 to /data/db//18
2025-12-15 19:54:14.017 Performing Consistency Checks
2025-12-15 19:54:14.017 -----------------------------
2025-12-15 19:54:14.017 Checking cluster versions                                     ok
2025-12-15 19:54:14.150 Checking database connection settings                         ok
2025-12-15 19:54:14.615 Checking database user is the install user                    ok
2025-12-15 19:54:14.620 Checking for prepared transactions                            ok
2025-12-15 19:54:14.620 Checking for contrib/isn with bigint-passing mismatch         ok
2025-12-15 19:54:14.620 Checking for valid logical replication slots                  ok
2025-12-15 19:54:14.732 Checking for subscription state                               ok
2025-12-15 19:54:15.288 Checking data type usage                                      failed check: Checking for reg* data types in user tables
2025-12-15 19:54:15.288 
2025-12-15 19:54:15.288 Data type checks failed: 
2025-12-15 19:54:15.288 Your installation contains one of the reg* data types in user tables.
2025-12-15 19:54:15.288 These data types reference system OIDs that are not preserved by
2025-12-15 19:54:15.288 pg_upgrade, so this cluster cannot currently be upgraded.  You can
2025-12-15 19:54:15.288 drop the problem columns and restart the upgrade.
2025-12-15 19:54:15.288 
2025-12-15 19:54:15.288 A list of the problem columns is in the file:
2025-12-15 19:54:15.288     /data/db/18/pg_upgrade_output.d/20251215T205413.934/tables_using_reg.txt

WIth tables_using_reg.txt containing

In database: fider
  public.posts.language

[mattwoberts]

Ah annoyingly that's a pretty new column too. I think that perhaps we should have just used text for that column and then cast it to the regconfig column in the query, I think that would work...

[dani]

As a work arround, I dumped the DB, droped it, done the upgrade, and restored it

[samstride]

@mattwoberts , any chance that this will be fixed in the next release?

[mattwoberts]

I've not yet done anything on this. I guess the best way forwards would be a new migration to sort this out, then you can upgrade to that version and then psql will let you upgrade....

I'll try to get something this week.