Is the discussion http://irclogs.ubuntu.com/2014/08/11/%23ubuntu- mir.html ?
If u-s-c doesn't always accept the --vt option then then it's going to fail on kernels that have VT support (which from the above log seems to be this particular case?). If VT support is available then LightDM assigns VTs to each server / system compositor so they don't conflict. In the phone case we only have one system compositor but theoretically you could also start an X server so LightDM has to assign VTs if they exist. There seem to options to solve this properly: 1. u-s-c always supports --vt and only applies it for backends that require it. 2. u-s-c backends that use VTs reads the XDG_VTNR environment variable. I would recommend option 2 since VTs are going to be a legacy feature in the future anyway and other systems seem to be using XDG_VTNR over command line options. ** Changed in: lightdm Importance: Undecided => Medium ** Changed in: lightdm Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to unity-system-compositor in Ubuntu. https://bugs.launchpad.net/bugs/1355005 Title: [regression] unity-system-compositor can't start (Unknown command line options: --vt 1) via lightdm on Android Status in Light Display Manager: Incomplete Status in Mir: Invalid Status in Mir 0.6 series: Invalid Status in Unity System Compositor: In Progress Status in “unity-system-compositor” package in Ubuntu: Fix Released Bug description: From Cemil: Sync'ed up 0.6 with devel@r1831 since we were in TRAINCON-0. Everything built successfully. Using image #179 with 0.6, mir itself works (i.e. mir-demos & nested), but USC has the following error : root@ubuntu-phablet:~# cat /var/log/lightdm/unity-system-compositor.log Unknown command line options: --vt 1 The "vt" option is passed in by the wrapper in lightdm, but not sure why usc is rejecting it. Without 0.6, usc works fine with the same set of args. It'd be nice if the AUS, or EUR can take a look on Mon. Follow the instructions (updated due to platform versioning) below to install and test : http://pastebin.ubuntu.com/7993688/ To manage notifications about this bug go to: https://bugs.launchpad.net/lightdm/+bug/1355005/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp