[tz] Troubles with zone Asia/Gaza after tzdata2020b release

[Brian Inglis]

On 2021-03-02 01:49, Evgheni Antropov via tz wrote:
> On Tuesday, March 2, 2021 01:59, Paul Eggert wrote:
>> On 3/1/21 1:19 PM, Tim Parenti via tz wrote:

>> Another possibility is that Evgheni is using a stripped down library that 
>> ignores both data blocks, and uses only the TZ string at the end.
>> Such a library does not conform to Internet RFC 8536 but might be suitable for 
>> stripped down devices such as a router. For Asia/Gaza, the TZ string is 
>> TZ='EET-2EEST,M3.4.4/48,M10.4.4/49', where the "48" and "49" rely on the 
>> extension specified in Internet RFC 8536 section 3.3.1 and scheduled to appear 
>> in a future POSIX release. If Evgheni's library doesn't support that extension 
>> then that's the problem.
>> 
>> Yet another possibility is that Evgheni's library simply ignores the TZ string. 
>> '-b slim' relies on the TZ string even for current timestamps, whereas '-b fat' 
>> fills out entries through 2038. However, if this were the issue I expect it 
>> would happen for timezones other than Asia/Gaza.
>> 
>>> Why is the system you're testing only looking at the (legacy) 32-bit data
>>> in the v1 data block, and not using the 64-bit data in the v2+ data
>>> block?  Please let us know more about the system you're running
>>>  >>> Please let us know more
>>> about the system you're running
>> 
>> Yes, that'd be helpful.

 > Thank you for attention to this issue.
 >
 > We're using tzdata on the our embedded devices with ARMv7 Processor rev 2 (v7l),
 > which has vanilla kernel
 > [root at Router8:~]# uname -a
 > Linux Router8 4.4.19-gdb0b54cdad #49 PREEMPT Mon Sep 30 15:10:54 EEST 2019
 > armv7l GNU/Linux
 >
 > Whole filesystem was compiled using Yocto Project 1.5 (poky-dora-10.0.0)
 > https://old.yoctoproject.org/releases-yocto-version/yocto-project-15-dora
 > <https://old.yoctoproject.org/releases-yocto-version/yocto-project-15-dora>
 >
 > Tzdata was compiling on Ubuntu 18.04 without any additional flags and
 > cross-compilers, just simple make install
 >
 > #!/bin/sh
 > make clean
 > #For compiling source extract tzdata and tzcode in one directory and run:
 > make TOPDIR=$(pwd)/binaries install
 >
> with additional changes related with requests from our several customers,
> which are not effecting on the this file. >
 > In attachment you can see whole listing of compilation.

This may be less useful than knowing what libc code is being used on tzdata.

The Yocto/OpenEmbedded project seems to be a system for managing recipes to 
apply thousands of patches to upstream components and tools on multiple host 
platforms.

It appears from yocto docs and links, that depending on the yocto version, it 
may be based on OpenEmbedded with some earlier trimmed embedded version of glibc 
(perhaps 2.24 as of yocto 2.2) or musl (version?) libc, which may not have 
tzcode changes merged to handle current tzdata formats.

Traditionally glibc/libc... use requires libc-bin which packages utilities 
including zic, zdump built using system libc conventions and structures.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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