instantiating QML MediaStore component crashes if index can't be opened

[Josué]

App crashes during start.
This app just works for me 1 time each 6 times proximately in all versions that I used from ubuntu (bq 4.5 ubuntu edition)

This is one of the logs from one crash:

ThumbnailerImageResponse::dbusCallFinished(): D-Bus error: "Request cancelled"
libust[15292/15337]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15292/15336]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
UbuntuWindow::handleSurfaceFocusChange(focused=false)
** Application is now inactive
libust[15457/15460]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15460]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15461]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15461]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
Loading module: 'libubuntu_application_api_touch_mirclient.so.3.0.0'
/usr/lib/arm-linux-gnueabihf/qt5/bin/qmlscene: unrecognized option '--url='
/usr/lib/arm-linux-gnueabihf/qt5/bin/qmlscene: invalid option -- 'I'

(process:15457): dconf-WARNING **: Unable to open /custom/xdg/data/dconf/profile/custom: Permission denied

(process:15457): dconf-WARNING **: unable to open named profile (custom): using the null configuration.
libust[15457/15483]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15483]: Error: Error opening shm /lttng-ust-wait-5 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15484]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
libust[15457/15484]: Error: Error opening shm /lttng-ust-wait-5-32011 (in get_wait_shm() at lttng-ust-comm.c:958)
terminate called after throwing an instance of 'std::runtime_error'
  what(): Tried to open a db with schema version -1, while supported version is 9.

In this file there was also advices saying that numerous thumbnailer request was failed but I think that it is normal...
If you need the complete log just tell me.

I talk with some people that told me that the app works fine form them so i think that maybe the app is trying to open some corrupted files or files that it can't manage.
Additional info: I'm using as /home/phablet/Music folder a symbolic link for my SD card Music folder.

[Andrew Hayzen (ahayzen)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

The app has failed to start here due to your mediascanner2 database being incorrect, also in bug 1514522 you can see that the database is locked. Could you provide you mediascanner2 log located at /home/phablet/.cache/upstart/mediascanner-2.0.log ?

[Josué (j2g2rp)]

Sure
Its too big (50mb approximately). You need the complete file or just a part in particular?

[Andrew Hayzen (ahayzen)]

Wow! Its probably looping, for example its known if you have a webm file on your device it can cause mediascanner2 to loop and crash (bug 1508142).

If you can spot a repeated pattern of failure messages, it would be useful to attach that, and if you can find the last non error messages they may be useful as well.

[Josué (j2g2rp)]

Oups, it's true. It's looped 802 times.
Attached you will find the first loop. I don’t know if it will be useful.
Please tell me if you need something else.

[Victor Thompson (vthompson)]

Marking mediascanner2 as affected.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Launchpad Janitor (janitor)]

This bug was fixed in the package mediascanner2 - 0.110+16.04.20151216-0ubuntu1

---------------
mediascanner2 (0.110+16.04.20151216-0ubuntu1) xenial; urgency=medium

  [ James Henstridge ]
  * Fix up handling of directory renames, so old contents is correctly
    removed from the index and inotify watches for subdirectories are
    cleaned up. (LP: #1460411)
  * If the mediascanner index can not be opened, catch the exception in
    the QML plugin and act as if the database is empty. A warning is
    printed via Qt's logging framework. This prevents QML apps using
    mediascanner from terminating if there is a problem opening the
    media index. (LP: #1514517)

  [ CI Train Bot ]
  * debian/libmediascanner-2.0-3.symbols: update to released version.

 -- James Henstridge <email address hidden> Wed, 16 Dec 2015 08:04:43 +0000