Black screen with cursor

[Ads20000]

I added the unity8-lxc PPA ('ppa:unity8-desktop-session-team/unity8-preview-lxc'), installed unity8-lxc and then used `sudo unity8-lxc-setup` and `sudo unity8-lxc-setup --rebuild-all` when the download of the ISO hanged (the command with the --rebuild-all flag would restart downloading from where it left off).

Before and after rebooting, I couldn't log into the Unity 8 LXC session using LightDM. After pressing Enter, it didn't load the session as I expected. The fonts went a bit odd on LightDM and the password box disappeared and the box on the left could no longer be interacted with. I could still click the indicators in the top-right however and shut down with them.

Linked: bug #1439291

[Christopher Townsend (townsend)]

Hi Ads20000,

Thank you for taking time to enter this bug report.

The issue is due to the recent transition from upstart to systemd. The unity8-lxc uses the Ubuntu Next daily ISO which is now systemd based. Certain services don't need to run in this particular use case and I'm having a hard time trying to keep systemd from starting them even though I'm telling it not to. I'm working with other people on trying to fix this, but as of right now, it's utterly broken:(

[Ads20000 (ads20000)]

Haha, thanks for the response, first time I've reported a Critical bug lol!
Yeah, I didn't realize the transition would hit Unity 8 in LXC so hard! That's annoying, especially considering the transition seems to be going well elsewhere. I hope it gets resolved soon so I can get testing Unity 8 right from my Trusty laptop, good luck! :D

[Christopher Townsend (townsend)]

I'm going to switch back to Upstart inside the container for now while I work out the systemd kinks. Also, lxc/cgmanager in Trusty does not work with systemd based containers anyways (see bug #1347020), so this is necessary until that is fixed.

[Christopher Townsend (townsend)]

Well, I tried this with a Trusty host and it seems Trusty cannot handle the Ubuntu Next ISO right now. When I start the container, it does not get an IP address, so I can't install the upstart-sysv package. I'm afraid this is going to be broken on Trusty until LXC and/or cgmanager can be updated which is out of my hands:(

[Ads20000 (ads20000)]

Thanks for trying Christopher, it would've been a nice solution for me to try out Ubuntu Next but oh well, does LXC or cgmanager need to be tagged onto this bug or does a separate bug need to be filed? Can you do that? Also is it that LXC/cgmanager need a new, Trusty-specific, version or do they just need a generic update which could be put in a Trusty PPA?

[Ads20000 (ads20000)]

Also could you remark the bug to Triaged since you can't work on the bug until the LXC/cgmanager update occurs?

[Ads20000 (ads20000)]

Oh never mind, I can see the other bug you've filed, thanks! It's annoying I can't delete my own comments :(

[Christopher Townsend (townsend)]

I'm pretty sure I have a workable solution for this. I've done the following:

1. Upload new cgmanager, lxc, and lxcfs to ppa:unity8-desktop-session-team/unity8-preview-lxc
2. Fixed the rootfs builder to download upstart-sysv and add it to the rootfs, then start the container and install it.
3. Fixed up the config builder to account for the nex lxc package.

I'm about to push the changes to the development branch and then I'll kick off a daily build and the PPA should be updated.

Note that 'unity8-lxc-setup --rebuild-config --rebuild-rootfs' will need to be run after updating the package.

[Ads20000 (ads20000)]

I get this when running the command:

~$ sudo unity8-lxc-setup --rebuild-config --rebuild-rootfs
Unpacking the ISO image...
Configuring the Unity8 LXC...
Traceback (most recent call last):
  File "/usr/bin/unity8-lxc-setup", line 300, in <module>
    subprocess.call(["dget", dget_url])
  File "/usr/lib/python3.4/subprocess.py", line 533, in call
    with Popen(*popenargs, **kwargs) as p:
  File "/usr/lib/python3.4/subprocess.py", line 848, in __init__
    restore_signals, start_new_session)
  File "/usr/lib/python3.4/subprocess.py", line 1446, in _execute_child
    raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: 'dget'

Before running the command, loading from LightDM got to a black screen with a mouse pointer. Will try again now but I suspect it won't work because of those errors.

[Ads20000 (ads20000)]

Yep, after running the command I still have the same error (probably due to the errors showing up in the Terminal). Also I can't switch to a logon teminal when I get to the black screen and have to use the power button on the computer to shut down from it.

[Christopher Townsend (townsend)]

Ah, dang, I forgot dget is part of the devscripts package which is not installed by default. I'll either use something that is already installed or depend on devscripts.

Thanks for letting me know! And sorry for all the issues you are running in to:(

[Ads20000 (ads20000)]

So I've updated again (which included a unity8-lxc update). I now get the following in my Terminal (and trying to load Unity 8 in LXC from LightDM still results in the mouse on the black screen):

$ sudo unity8-lxc-setup --rebuild-config --rebuild-rootfs
Unpacking the ISO image...
Configuring the Unity8 LXC...
--2015-04-12 13:47:55-- http://archive.ubuntu.com/ubuntu/pool/main/u/upstart/upstart-sysv_/bin/sh:%201:%20rmadison:%20not%20found_amd64.deb
Resolving archive.ubuntu.com (archive.ubuntu.com)... 91.189.91.14, 91.189.91.15, 91.189.91.23, ...
Connecting to archive.ubuntu.com (archive.ubuntu.com)|91.189.91.14|:80... connected.
HTTP request sent, awaiting response... 404 Not Found
2015-04-12 13:47:59 ERROR 404: Not Found.

Starting the container
Switching to upstart...
lxc_container: lsm/apparmor.c: apparmor_process_label_set: 183 No such file or directory - failed to change apparmor profile to lxc-container-default-with-nesting

[corrado venturini (corradoventu)]

I have same problem on vivid:
unity8 in lxc black screen with cursor on Vivid

I added the unity8-lxc PPA ('http://ppa.launchpad.net/unity8-desktop-session-team/unity8-preview-lxc/ubuntu vivid main'),
installed unity8-lxc and then used `sudo unity8-lxc-setup` and `sudo unity8-lxc-setup --rebuild-all`
... black screen with mouse arrow ... power off to reboot.
sudo unity8-lxc-setup --update-lxc ... failed with errors like in
https://bugs.launchpad.net/ubuntu/+source/unity8-lxc/+bug/1418671

sudo -i
and
unity8-lxc-setup --update-lxc
completed ok

after reboot on LightDM I selected unity8 in lxc, entered password ... black screen with mouse arrow.
the arrow follows the mouse, but I was unable to do anything.
CTRL+F1 has no effect, power off to reboot.

According suggestion in https://bugs.launchpad.net/ubuntu/+source/unity8-desktop-session/+bug/1320356
I attach some logs created at logon with unity 8 in lxc in: /var/log/lightdm/

[Giovanni Panozzo (giox069)]

I have the same problem pointed in post #14 and in the subject of this bug, but I'm using Ubuntu 15.04.
After installing unity8-lxc, I choose unitu8 lxc at the logon screen. But the only thing I can get, is a black screen with only the mouse pointer.
I followed this guide: https://wiki.ubuntu.com/Unity8inLXC using both the "stock" provided packages (first test), and the PPA ppa:unity8-desktop-session-team/unity8-preview-lxc (second test).
Nothing changes: black screen with only mouse cursor.
I tested it on three PC: a core i5 4xxx with integrated intel graphic card, a Core 2 Duo with NVIDIA and opensource driver, and an AMD CPU based PC with an ATI card and opensource driver (raeon module).
All three machines shows the same black screen with only the mouse cursor.

[Ads20000 (ads20000)]

Should work with the most recent unity8-lxc updates. Just make sure you've got the updates and then use `sudo unity8-lxc --redownload` and `sudo unity8-lxc --rebuild-config --rebuild-rootfs`. Then try to log into the Unity 8 LXC session. You might need to be a little patient...

If it still produces a black screen with a cursor just change the status back to 'Confirmed'.

[Christopher Townsend (townsend)]

Hey Ads20000,

Thanks for the update. Regarding the bug status, let's keep it "In Progress" for now. These bug statuses are intended for the trunk branch and for the archive version of unity8-lxc and it helps me keep track of what changes still need to get in the main code.

Thanks!

[Launchpad Janitor (janitor)]

This bug was fixed in the package unity8-lxc - 1.0.4+15.10.20150609-0ubuntu1

---------------
unity8-lxc (1.0.4+15.10.20150609-0ubuntu1) wily; urgency=medium

  [ Chris Townsend ]
  * Bump version to 1.0.4.
  * Automount /proc to avoid a race when attaching to a container to run
    a command. Also remove the ugly sleep workaround. (LP: #1428848)
  * Cache a copy of upstart-sysv when downloading the Unity 8 Desktop
    Next ISO image. This will keep the ISO and the upstart-sysv package
    in sync. (LP: #1458236)
  * Catch the exception when distro-info-data is outdated during dev
    release transitions. Use the current stable release instead when the
    dev release has not been updated. (LP: #1448521)
  * Terminate the session instead of killing the user when logging out
    of the Unity 8 LXC session. This is much less aggressive and keeps
    ssh sessions alive. (LP: #1456604)
  * Use upstart-sysv in the Unity8 container instead of systemd. This
    fixes a slew of issues when using systemd in the container. (LP:
    #1437900)

 -- CI Train Bot <email address hidden> Tue, 09 Jun 2015 14:17:23 +0000