[phobos] std.datetime unittest

[Jonathan M Davis]

On Wednesday, January 04, 2012 04:55:17 Martin Nowak wrote:
> I regularly get a failing phobos unittest.
> 
> core.exception.AssertError at std/datetime.d(28169): _assertPred!"==" failed:
> [PPT] is not == [PDT].
> 
> As I am the only one it might be related to updating to FreeBSD9.
> How can I check that the timezone files are correct?
> Are there tools to decode timezone files?

Well, the FreeBSD box on the autotester is fine, though I don't know what 
version of FreeBSD it's using. Your failure is just downright bizarre though. 
According to 
http://www.timeanddate.com/worldclock/timezone.html?n=137&syear=1925 that 
abbreviation was used for daylight savings time in America/Los_Angeles between 
1925 and 1949. The test tests it for the current time.

The question, therefore, is what time zone your box is set to. It could be 
that setTZEnvVar isn't working correctly on your box. However, there don't 
appear to be an time zones which currently use PPT for daylight savings time, 
so I don't know that it's likely that that's causing the problem.

I suppose that the time zone files _could_ be corrupt, but that seems unlikely, 
since it would fail to load if it didn't match the spec. More likely, the time 
zone file is just wrong, but that would be weird, since theoretically, they all 
come from the same source.

If you want to look at what's in the time zone file, then use zdump. If you use 
it with -v, it'll spit out a bunch of lines looking like this:

America/Los_Angeles  Sun Mar  8 10:00:00 2493 UTC = Sun Mar  8 03:00:00 2493 
PDT isdst=1

Each of them represents a DST switch. On my computer (64-bit Linux), if I run

zdump America/Los_Angeles -v | grep PPT

then I get

America/Los_Angeles  Tue Aug 14 23:00:00 1945 UTC = Tue Aug 14 16:00:00 1945 
PPT isdst=1
America/Los_Angeles  Sun Sep 30 08:59:59 1945 UTC = Sun Sep 30 01:59:59 1945 
PPT isdst=1

If you're seeing more than those two lines, then something is definitely wrong 
with your time zone file.

You could also tar up you /usr/share/zoneinfo directory, and I can have a look 
at it, but zdump should be enough to tell you whether too many DST switches in 
America/Los_Angeles use PPT. And if you're only getting those two lines, then 
something else weird is going on that needs to be looked into.

- Jonathan M Davis