Date: Wed, 5 Jun 2019 10:47:35 +0200
From: Christoph Berg <myon@debian.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: UCT (Re: pgsql: Update time zone data files to tzdata release
 2019a.)
Message-ID: <20190605084735.GC15829@msg.df7cb.de>
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	Tom Lane <tgl@sss.pgh.pa.us>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>
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Re: Tom Lane 2019-06-04 <65800.1559662051@sss.pgh.pa.us>
> > There is something wrong here. On Debian Buster/unstable, using
> > system tzdata (2019a-1), if /etc/timezone is "Etc/UTC":
> 
> Is your build using --with-system-tzdata?  If so, which tzdb
> release is the system on, and is it a completely stock copy
> of that release?

It's using system tzdata (2019a-1).

There's one single patch on top of that:

https://sources.debian.org/src/tzdata/2019a-1/debian/patches/

> BTW, does Debian set up /etc/timezone as a symlink, by any chance,
> rather than a copy or hard link?  If it's a symlink, we could improve
> matters by teaching identify_system_timezone() to inspect it.

In the meantime I realized that I was only testing /etc/timezone
(which is a plain file with just the zone name), while not touching
/etc/localtime at all. In this environment, it's a symlink:

lrwxrwxrwx 1 root root 27 Mär 28 14:49 /etc/localtime -> /usr/share/zoneinfo/Etc/UTC

... but the name still gets canonicalized to Etc/UCT or UCT.

Christoph