From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andrew Dunstan <andrew@dunslane.net>
Cc: Andres Freund <andres@anarazel.de>
Cc: pgsql-hackers@postgresql.org, Peter Eisentraut <peter_e@gmx.net>
Cc: Petr Jelinek <petr@2ndquadrant.com>
Subject: Re: 002_types.pl fails on some timezones on windows
Date: Thu, 30 Sep 2021 15:38:38 -0400
Message-ID: <3204190.1633030718@sss.pgh.pa.us> (raw)
In-Reply-To: <f4b9c195-7caa-4849-ba67-49a5d153e203@dunslane.net>
References: <20210930183641.7lh4jhvpipvromca@alap3.anarazel.de>
<f4b9c195-7caa-4849-ba67-49a5d153e203@dunslane.net>
Andrew Dunstan <andrew@dunslane.net> writes:
> On 9/30/21 2:36 PM, Andres Freund wrote:
>> CI showed me a failure in 002_types.pl on windows. I only just now noticed
>> that because the subscription tests aren't run by any of the vcregress.pl
>> steps :(
> We have windows buildfarm animals running the subscription tests, e.g.
> <https://buildfarm.postgresql.org/cgi-bin/show_stage_log.pl?nm=drongo&dt=2021-09-29%2019%3A08%3A2...;
> and they do it by calling vcregress.pl.
But are they running with the prevailing zone set to "Greenwich Standard
Time"?
I dug around to see exactly how we handle that, and was somewhat
gobsmacked to find this mapping in findtimezone.c:
/* (UTC+00:00) Monrovia, Reykjavik */
"Greenwich Standard Time", "Greenwich Daylight Time",
"Africa/Casablanca"
According to current tzdb,
# Zone NAME STDOFF RULES FORMAT [UNTIL]
Zone Africa/Casablanca -0:30:20 - LMT 1913 Oct 26
0:00 Morocco +00/+01 1984 Mar 16
1:00 - +01 1986
0:00 Morocco +00/+01 2018 Oct 28 3:00
1:00 Morocco +01/+00
Morocco has had weird changes-every-year DST rules since 2008, which'd
go a long way towards explaining funny behavior with this zone, even
without the "reverse DST" since 2018. And sure enough, 002_types.pl
falls over with TZ=Africa/Casablanca on my Linux machine, too.
I'm inclined to think we ought to be translating that zone name to
Europe/London instead. Or maybe we should translate to straight-up UTC?
But the option of "Greenwich Daylight Time" suggests that Windows thinks
this means UK civil time, not UTC.
I wonder if findtimezone.c has any other surprising Windows mappings.
I've never dug through that list particularly.
regards, tom lane
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To: pgsql-hackers@postgresql.org
Cc: tgl@sss.pgh.pa.us, andrew@dunslane.net, andres@anarazel.de, peter_e@gmx.net, petr@2ndquadrant.com
Subject: Re: 002_types.pl fails on some timezones on windows
In-Reply-To: <3204190.1633030718@sss.pgh.pa.us>
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