ubuntu-phone team mailing list archive

[Alexander Sack <asac@xxxxxxxxxxxxx>]

On Thu, Feb 27, 2014 at 12:16 AM, Bill Filler <bill.filler@xxxxxxxxxxxxx> wrote:
> On 02/26/2014 05:22 PM, Ricardo Salveti de Araujo wrote:
>> On Wed, Feb 26, 2014 at 2:27 PM, Didier Roche <didrocks@xxxxxxxxxx> wrote:
>>> Hey,
>>>
>>> Some desktop only update are still flowing in through CI Train, however, we
>>> are still blocked by not being able to get one image promotable.
>>>
>>> Otherwise, two images were produced:
>>> #208 contained the second part of the sdk fix for the alarm
>>> #209 contains a libhybris change to protect bionic properties call.
>>>
>>> Here are the updates on current known regressions:
>>>
>>> 2. Unity8 (Michał/Ricardo)
>>> It seems there is a crash, debug symbols on the android side are building,
>>> Michał and Ricardo are looking into those. Seems it's maybe not Android-side
>>> related but a gcc 4.7 vs 4.8 ABI mismatch. Ricardo is trying to disable tls
>>> for more information.
>>>
>>> The investigation is still ongoing with Ricardo trying to disable multiple
>>> flags to see if that helps.
>> We spent some more time on this issue, and were able to check that
>> it's not related with Unity8 itself, but with Qt (v8 engine). It
>> crashes in the heap when it's trying to find the inline function
>> generator, which is the same crash we had with qmlscene and
>> gallery-app.
>>
>> That's probably why removing the android TLS blocks, and also dropping
>> any pthread allocation inside libhybris didn't make any difference.
>> We're not yet sure what might be causing this behavior now, but hard
>> to say it's really because of 4.4.2 at this point.
>>
>> ricmm was also trying to understand the crash a bit better, but not
>> sure if he got any further.
>>
>> At the same time I also tried to reproduce this issue with Qt5.2, and
>> noticed that this crash is gone, but there is still another crash when
>> running the unity8 autopilot test cases. Opened bug
>> https://bugs.launchpad.net/ubuntu/+source/qtdeclarative-opensource-src/+bug/1285385
>> for this one (on the good side we finally have a useful stack trace
>> now).
>>
>>> 3. QMLScene crash (Timo + SDK team)
>>> -> Timo told that this is in the V8 code and the experts don't have time and
>>> want to get Qt 5.2 asap rather.
>>>
>>> Another crash today, same than the one yesterday.
>> This seems to be the only crash actually :-) As we have a completely
>> different V8 implementation with Qt5.2 (old one is now dead), it's
>> going to be hard to find a fix for this guy with the 5.0 stack.
> Thanks for doing so much hard work and analyzing the problem Ricardo!
>
> Asac: Now that we understand this issue only happens with Qt 5.0, are we
> in agreement to not waste any more time on it as we're moving to Qt5.2
> very shortly and the V8 crash is gone?

Over the years I have become a strong believer of the principle that
if you want to fix something the only approach is to fix the present
and not the future as otherwise the present will obviously never be
fixed. I would love to see all Ubuntu Engineering understanding and
living this principle :).

Anyway regardless of this fine line, we might indeed do what you
suggest. Give us some time to discuss how to best do the landing dance
to 5.2.


 - Alexander




>
>
>>
>> Cheers,
>
>
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