[postgis-devel] ERROR: operator class "brin_geography_inclusion_ops" does not exist for access method "brin"

[Regina Obe]

> It seems very possible that postgis was not upgraded between versions as
you
> intended.  My usual procedure is to install the newest postgis for both
the old
> and new postgres version, and then run postgis_upgrade.sql, and then run
> pg_upgrade.  But until recently I never ran ALTER EXTENSION postgis
> UPGRADE, nor postgis_extensions_upgrade() - unless that's enforced, it
> probably can't be assumed that someone did that.
[Regina Obe] 
Well in pre-PostGIS 3.0 if you never did that and were using extensions,
then you never really upgraded because prior versions of postgis had
distinct binaries for each minor.
So for example postgis-2.5.so postgis-2.4.so and so on.  
It was only in PostGIS 3.0 that we dropped the minor in the binary by
default.  So perhaps you had all those lying around.

When did you switch from non-extension to extension version?
It really shouldn't matter if you were using a pre-released version or not
as we use the same script to upgrade all and all extension files are just a
copy of the main ANY one.  The different script files is just a nuisance
imposed on us by PostgreSQL extension machinery.

But I'll see if I can simulate a regular (one pg upgraded from 9.4 to 3.2 )
and then a half broken install - one that was upgraded from 9.4 to a version
before we made the fix and then pg_upgraded to 3.2