Bug 748936 - QML demos (and most other things using QtDeclarative) are crashing
QML demos (and most other things using QtDeclarative) are crashing
Product: Fedora
Classification: Fedora
Component: qt (Show other bugs)
Unspecified Unspecified
unspecified Severity unspecified
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Assigned To: Rex Dieter
Fedora Extras Quality Assurance
: 749015 (view as bug list)
Depends On:
  Show dependency treegraph
Reported: 2011-10-25 11:51 EDT by Slawomir Czarko
Modified: 2013-10-04 08:31 EDT (History)
9 users (show)

See Also:
Fixed In Version: qt-4.7.4-6.fc15
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2011-11-14 17:27:13 EST
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
Qt Creator backtrace by Slawomir Czarko (24.64 KB, text/plain)
2011-10-26 08:11 EDT, Kevin Kofler
no flags Details

External Trackers
Tracker ID Priority Status Summary Last Updated
Qt Bug Tracker QTBUG-18906 None None None Never
Qt Bug Tracker QTBUG-19736 None None None Never

  None (edit)
Description Slawomir Czarko 2011-10-25 11:51:40 EDT
Description of problem:

I'm trying to run QML demos from qt-demos in /usr/lib/qt4/demos/declarative/

Some of them run but many fail with segmentation fault.

The demos which fail:

Most crash during initialization.

photoviewer crashes a few seconds after showing main window.
twitter crashes when "search" button is pressed

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1. Load one of the demos with qmlviewer or run it in Qt Creator
Actual results:

Expected results:

Additional info:
Comment 1 Kevin Kofler 2011-10-26 07:37:41 EDT
*** Bug 749015 has been marked as a duplicate of this bug. ***
Comment 2 Rex Dieter 2011-10-26 07:47:20 EDT
Fwiw, all those referenced demos are ok on my f14/x86_64 box.
Comment 3 Kevin Kofler 2011-10-26 08:11:44 EDT
Created attachment 530276 [details]
Qt Creator backtrace by Slawomir Czarko

I extracted the backtrace of the relevant thread from:

I can reproduce the crash in the calculator demo (not tested the others nor Qt Creator yet) with qt-x11-4.7.4-2.fc15.i686. The backtrace appears to match the Qt Creator one, but I haven't installed qt-x11-debuginfo yet, so there's a lot of information missing, and so I can't tell for sure.
Comment 4 Jaroslav Reznik 2011-11-03 12:17:01 EDT
Hit the same issue and I can confirm it's ok within Qt SDK (upstream Qt build) so it has to be something in our packaging or g++/whatever issue.
Comment 5 Kevin Kofler 2011-11-03 12:22:38 EDT
KAN EYE HAZ VALGRIND LOGZ PLZ LOL??????????!!!!!!!!?????????????

[insert picture of cute kitten here]

Comment 6 Jaroslav Reznik 2011-11-03 12:28:19 EDT
According to upstream's bug report (one of duplicates), -O2 -fno-strict-aliasing is working workaround.
Comment 7 Kevin Kofler 2011-11-03 12:30:40 EDT
Right, according to the upstream tracker, this is an aliasing issue.
Comment 8 Rex Dieter 2011-11-03 14:15:38 EDT
Found a couple of aliasing problems, once we looked closer,

* Thu Nov 03 2011 Rex Dieter <rdieter@fedoraproject.org> 1:4.7.4-6
- build declarative/qml with -fno-strict-aliasing (#748936, QTBUG-19736)
- build tds sql driver with -fno-strict-aliasing

Build queue'd:
Comment 9 Fedora Update System 2011-11-04 09:59:53 EDT
qt-4.7.4-6.fc15 has been submitted as an update for Fedora 15.
Comment 10 Fedora Update System 2011-11-05 19:56:38 EDT
Package qt-4.7.4-6.fc15:
* should fix your issue,
* was pushed to the Fedora 15 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing qt-4.7.4-6.fc15'
as soon as you are able to.
Please go to the following url:
then log in and leave karma (feedback).
Comment 11 Fedora Update System 2011-11-14 17:27:13 EST
qt-4.7.4-6.fc15 has been pushed to the Fedora 15 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 12 Red Hat Bugzilla 2013-10-03 20:21:37 EDT
Removing external tracker bug with the id '18906' as it is not valid for this tracker
Comment 13 Red Hat Bugzilla 2013-10-03 20:21:41 EDT
Removing external tracker bug with the id '19736' as it is not valid for this tracker

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