System compositor fails to start - Failed to set the current VT mode: Input/output error (5)

The specific problem here is in unity-system-compositor.log - Mir fails to control the VT and throws an exception:

ERROR: /build/buildd/mir-0.0.5bzr774saucy0/src/server/graphics/gbm/linux_virtual_terminal.cpp(137): Throw in function virtual void mir::graphics::gbm::LinuxVirtualTerminal::register_switch_handlers(mir::MainLoop&, const std::function<bool()>&, const std::function<bool()>&)
Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<std::runtime_error> >
std::exception::what: Failed to set the current VT mode
[boost::errinfo_errno_*] = 5, "Input/output error"

Annoyingly for some reason the log in comment 1 seems corrupt. The lightdm.log from comment 19 in bug 1109957 doesn't have corruption.

Also note the log shows that LightDM tried to run standard X after the compositor fails, but in both Fernando and Mark's case it doesn't seem to have worked correctly.

Oddly, this morning my laptop booted straight into Mir with no problems. Either the issue is fixed for me, or it's racy and I just (finally!) got lucky.

This bug has been reported on the Ubuntu Package testing tracker.

A list of all reports related to this bug can be found here:
http://packages.qa.ubuntu.com/qatracker/reports/bugs/1195509

I've tried this morning again and it's working now. I could see the two pointers and also the unity-system-compositor process running.
However, while updating this bug my session ended abruptly and I was kicked out back into the lightdm login screen. After login, no more crashes.

Attaching the new log files

I'm suggesting we close this, there has been a handful of bugs fixes/development which has occured in recent weeks to address these boot issues. It appears we're fairly stable/reliable for boot. Please reopen if your experience is still failing to boot on the system-compositor-testing ppa circa first week of July or later.

Reopened from duplicate bug 1201793.

Fix committed into lp:mir at revision None, scheduled for release in mir, milestone 0.0.9

these are the 2 relevant competing bugs...
https://bugs.launchpad.net/xmir/+bug/1206508 "Xorg crash on xmir punts user back out to greeter" which is the ctl+c issue on sw rendering - which this mp https://code.launchpad.net/~thomas-voss/mir/revert-process-group-leader-patch/+merge/177645 was intending to fix

and this bug which is fixed by https://code.launchpad.net/~mlankhorst/mir/setsid/+merge/176676

I ran in to this again on intel machine.

ERROR: /build/buildd/mir-0.0.8+13.10.20130730bzr898saucy0/src/server/graphics/gbm/linux_virtual_terminal.cpp(137): Throw in function virtual void mir::graphics::gbm::LinuxVirtualTerminal::register_switch_handlers(mir::MainLoop&, const std::function<bool()>&, const std::function<bool()>&)
Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<std::runtime_error> >
std::exception::what: Failed to set the current VT mode
[boost::errinfo_errno_*] = 5, "Input/output error"

apt-cache policy unity-system-compositorunity-system-compositor:
  Installed: 0.0.1bzr39saucy0.242
  Candidate: 0.0.1bzr39saucy0.242
  Version table:
 *** 0.0.1bzr39saucy0.242 0
       1002 http://ppa.launchpad.net/mir-team/system-compositor-testing/ubuntu/ saucy/main amd64 Packages
        100 /var/lib/dpkg/status
apt-cache policy mir-demos
mir-demos:
  Installed: 0.0.8+13.10.20130807.1bzr938saucy0
  Candidate: 0.0.8+13.10.20130807.1bzr938saucy0
  Version table:
 *** 0.0.8+13.10.20130807.1bzr938saucy0 0
       1002 http://ppa.launchpad.net/mir-team/system-compositor-testing/ubuntu/ saucy/main amd64 Packages
        100 /var/lib/dpkg/status
     0.0.8+13.10.20130807.1-0ubuntu1 0
        500 http://archive.ubuntu.com/ubuntu/ saucy/main amd64 Packages

Fix committed into lp:mir at revision 942, scheduled for release in mir, milestone 0.0.9

This bug was fixed in the package mir - 0.0.8+13.10.20130808.1-0ubuntu1

---------------
mir (0.0.8+13.10.20130808.1-0ubuntu1) saucy; urgency=low

  [ Robert Ancell ]
  * VT switch on alt+ctrl+Fn.
  * Add missing iostream import. This was accidentally removed in
    revision 939. Local builds and CI builds both seem to have treated
    this as a warning; debian package builds as an error. Fixes
    packaging builds.

  [ Robert Carr ]
  * Add an interface by which the shell may be notified of and interfere
    with surface configuration requests.

  [ Alexandros Frantzis ]
  * Bring back revision 931 with a fix for the crash it caused (LP:
    #1209053). (LP: #1209053)
  * examples: Quit the example servers and standalone programs when
    Ctrl+Alt+Backspace is pressed.

  [ Maarten Lankhorst ]
  * Re-introduce console support, and ignore control characters. (LP:
    #1102756, #1195509)

  [ Ubuntu daily release ]
  * Automatic snapshot from revision 944
 -- Ubuntu daily release <email address hidden> Thu, 08 Aug 2013 05:03:26 +0000