Re: pg_upgrade 9.4 -> 9.5 with pg_trgm fails for me - Mailing list pgsql-general

Karsten Hilbert <Karsten.Hilbert@gmx.net> writes:
> On Fri, Jan 08, 2016 at 04:03:51PM -0500, Tom Lane wrote:
>> BTW, the one-liner fix that I'd had in mind when I wrote that does indeed
>> fix this particular problem, but after studying the code I realized that
>> there's a whole bunch of related problems; for instance I believe
>> pg_upgrade would lose domain constraints on a domain type that's in an
>> extension installed into pg_catalog :-(.

> Does this warrant adding a few words to the documentation
> warning against installing extensions into pg_catalog. ?

No, it's just a bug.  Although apparently not many people do that, or
we'd have heard complaints before.

            regards, tom lane