/usr/lib/arm-linux-gnueabihf/indicator-datetime/indicator-datetime-service:5:reset_timer:unity::indicator::datetime::LiveClock::Impl::on_timerfd_cond:g_main_dispatch:g_main_context_dispatch:g_main_context_iterate

Confirmed, this is related to the TFD_TIMER_CANCEL_ON_SET change. Looks like timerfd_settime() is failing and setting errno to ECANCELED. This isn't listed as a possible error in the manpage but now that we're hitting ECANCELED a web search turns up the condition pretty quickly.

The ability to return ECANCELED was added was added for this use case:

<http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=99ee5315dac6211e972fa3f23bcc9a0343ff58c4>

> Some applications must be aware of clock realtime being set
> backward. A simple example is a clock applet which arms a timer for
> the next minute display. If clock realtime is set backward then the
> applet displays a stale time for the amount of time which the clock
> was set backwards. Due to that applications poll the time because we
> don't have an interface.
>
> Extend the timerfd interface by adding a flag which puts the timer
> onto a different internal realtime clock. All timers on this clock are
> expired whenever the clock was set.
>
> The timerfd core records the monotonic offset when the timer is
> created. When the timer is armed, then the current offset is compared
> to the previous recorded offset. When it has changed, then
> timerfd_settime returns -ECANCELED. When a timer is read the offset is
> compared and if it changed -ECANCELED returned to user space. Periodic
> timers are not rearmed in the cancelation case.
> http://www.spinics.net/lists/linux-tip-commits/msg11814.html

Likely solution: in indicator-datetime/src/clock-live.cpp, move the timerfd_create() call from LiveClock::Impl::Impl() to LiveClock::Impl::reset_timer(), also adding a test to close() the previous timer if it's not -1.

I will be able to start on this in ~10 hours when my jury duty is done for the day. If this bug is deemed as supercritical, please feel free to reclaim the ticket and fix it before then.

consider for ota crash fix

This bug was fixed in the package indicator-datetime - 13.10.0+15.04.20150301.1-0ubuntu1

---------------
indicator-datetime (13.10.0+15.04.20150301.1-0ubuntu1) vivid; urgency=medium

  [ CI Train Bot ]
  * New rebuild forced.

  [ Charles Kerr ]
  * create a new timerfd each time we need to call timerfd_settime().
    (LP: #1424966)
 -- CI Train Bot <email address hidden> Sun, 01 Mar 2015 06:08:10 +0000

This bug was fixed in the package indicator-datetime - 13.10.0+15.04.20150226~rtm-0ubuntu1

---------------
indicator-datetime (13.10.0+15.04.20150226~rtm-0ubuntu1) 14.09; urgency=medium

  [ Charles Kerr ]
  * Avoid ECANCELED errors in calls to timerfd_settime() (LP: #1424966)
 -- CI Train Bot <email address hidden> Thu, 26 Feb 2015 05:29:29 +0000