Mea culpa, I apologise to the list for misreading the source code.
My problem stemmed from pg_upgrade needing to have the superuser password available via PGPASS (or PGPASSWORD). It’s not clear why it included the word “postmaster” in the error message which sent me off down a rathole of “it has no idea what it’s doing, perhaps its connecting to the wrong instance, etc…”
>>> port 5432 failed: fe_sendauth: no password supplied could not connect to source postmaster started with the command
I do think that having it check for not having a password and actually announcing that up front would be an improvement, rather than doing the compatibility checks, etc and waiting until it tries to startup before failing cryptically.
Nevertheless, I have successfully upgraded my V16 to V18 using pg_upgrade on Windows 11.
I can’t see how I close the ticket, but it can certainly be closed as PEBKAC
Jeff
From: Andrew Dunstan <andrew@dunslane.net>
Sent: Wednesday, 4 February 2026 11:33 PM
To: David G. Johnston <david.g.johnston@gmail.com>; Jeff Laing <jeff.laing@spatialnetworx.ai>; pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #19392: PG_UPGRADE is non-functional on Windows
On 2026-02-04 We 1:43 AM, David G. Johnston wrote:
On Tuesday, February 3, 2026, PG Bug reporting form <noreply@postgresql.org> wrote:
The following bug has been logged on the website:
Bug reference: 19392
Logged by: Jeff Laing
Email address: jeff.laing@spatialnetworx.ai
PostgreSQL version: 18.1
Operating system: Windows 11
Description:
After struggling with it for a while, I’ve come to the conclusion that
PG_UPGRADE is not functional on Windows.
This is a very hard to accept premise and this bug report doesn’t support it.
pg_upgrade is tested on Windows all the time, both in the buildfarm and in CI, so the statement that it is not functional doesn't add up.
cheers
andrew
--
Andrew Dunstan
EDB: https://www.enterprisedb.com
