metacity (flashback) crashes and forces logout

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

Possibly-related: I currently have one Firefox window (only: of 14 FF windows) that spontaneously lost its canvas management area - all the outside bits that have the icons to close it, minimise it, resize it etc. I'll attach a screenshot. In addition, when I turned on power to my secondary monitor (where I had a FF window open with this bug report and a few other tabs), that window would not display on the 2nd monitor. In fact, although that FF window appears in the dock, I can't get to it or see it or work with it in any way - except that if I click on its icon in the dock, to hide or unhide it, I sometimes see two or three frames of the hide/unhide animation. Using alt-mousedown, I can't grab the window. I can drag other windows onto the 2nd monitor - it's working fine - but the bug-report FF window is not being rendered, nor is it grabbable in any way.

https://launchpad.net/~albertsmuktupavels/+archive/ubuntu/metacity-3-18

Please use above PPA to upgrade metacity. That is current upstream version (unreleased) that is supposed to fix few problems. Please report any problem you see with that version.

Okay, I've done that. I'll log out and back in again.

Okay, I've done that. I'll log out and back in again.

Actually, I rebooted, as I saw there was a kernel update I hadn't rebooted after applying. The reboot turned into the scary kind, for this Intel NUC, where I had to unplug not only all USB3 drives, but also the HDMI display before it would display the boot screen. But I'm back in action.

I'll let you know if there are further problems.

All Firefox windows are correctly decorated now, and the untouchable FF window on the 2nd monitor is also dispalying and functioning again properly.

I'm just reporting in that since upgrading metacity using Alberts' PPA, I have not experienced a further crash. The nearest I came was a screen-lock which I'm pretty sure I accidentally triggered via a Ctrl+Shift+L. :-) Since the frequency was something like every hour or two, I think that's a very healthy sign. Thanks, Alberts!

Hmm, that was weird: similarly to comment #4, I just noticed a Firefox window lose all its decorations, so to hide it I had to use its icon in the dock. But when I unhid it, the decorations were back. So: weird. I just thought I'd mention it.

Hello LukeKendall, or anyone else affected,

Accepted metacity into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/metacity/1:3.18.4-0ubuntu0.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Dmitry, please upload this to yakkety as well, otherwise this cannot land in -updates.

The link https://wiki.ubuntu.com/Testing/EnableProposed talks about Ubuntu 14.04 and something called Softwatre & Updates:

"To enable the proposed archive for Ubuntu 14.04 use the Software & Updates program and ensure that Pre-release updates (trusty-proposed) is ticked in the Updates tab."

Is "Software & Updates" the same thing as System Tools -> Administration -> Update Manager, or Software Updater?

I got a crash when I tried to start Software Updater (it asked if I wanted to report it as a I relaunched it: but relaunching just crashed again). When I chose Update Manager, the window appeared then vanished.

I've attached the excerpt from /var/syslog.

I saw a warning a few days ago stating that one of my repositories for trusty (extensions, IIRC) was not able to be fetched as its signature was missing or out of date, and so I went into Update Manager and unchecked the single repository that matched. That sounds relevant, as I'm running Ubuntu 16.04. Also possibly relevant is a red danger-triangle that has been appearing on the top status/widget bar in the Flashback/Metacity UI, related to system updates: none of the options provided via the warning icon's drop-down menu actually worked (I think the options included: check for updates, install updates), but I was able to run Synaptic and Mark All Upgrade and then Apply and the red warning triangle went away following the updates synpatic found and applied.

Ah, and starting synaptic now reports an error in a more friendly way:

E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/au.archive.ubuntu.com_ubuntu_dists_trusty-updates_main_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.
E: _cache->open() failed, please report.

I'll add another comment and attach that file, too: it looks binary to me.

I moved aside the file it was complaining about, which I just mentioned, so I could attach it here. However, by the end of this report, it had been removed by the package system. I had done this, thinking kit would keep it safe:

# mv /var/lib/apt/lists/au.archive.ubuntu.com_ubuntu_dists_trusty-updates_main_i18n_Translation-en /var/lib/apt/lists/aside-au.archive.ubuntu.com_ubuntu_dists_trusty-updates_main_i18n_Translation-en

But apparently the package system removes files it doesn't expect to see there, so I'm sorry, I can't give you the copy I had preserved and Browsed to (apparently launchpad doesn't up[load the file then, it waits till you finish filling in the form: bad decision, I guess!

Anyway, for now I've just moved that file aside. That allowed Synaptic to run ;properly, and now allows Software Updater to start; but after a while it reports "Failed to download repository information". Ah, and it has an "Updates|" tab, so probably it's the "Software & Updates" thing referred to on the URL provided. (It seems user-unfriendly to name it with the name that you see after you've found it and started it, not the name you area presented with to start running it in the first place!)

And I suppose you can work out that that page probably refers to releases other than Trusty, even though you have to read on to discover that, rather than communicating that up-front, and not mentioning Xenial or Yakkety at all.

But that said, there is no "Pre-release updates (xenial-proposed)" option, so I still don't know how I can comply with the request, unfortunately!

Ah, what the URL *also* doesn't tell you is that you first need to click over to the Developer Options tab and first select:
     Pre-released update (<NAME>-proposed)

Oh. Good thought, but even enabling that didn't make the new option appear under the Updates tab.

I then tried closing the updater, and it reported the software list was now out of date and needed reloading. After doing that, I got further error messages:

W:http://dl.google.com/linux/earth/deb/dists/stable/Release.gpg: Signature by key 4CCA1EAF950CEE4AB83976DCA040830F7FAC5991 uses weak digest algorithm (SHA1), W:An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://extras.ubuntu.com/ubuntu trusty Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 16126D3A3E5C1192, E:Failed to fetch http://dl.google.com/linux/earth/deb/dists/stable/Release No Hash entry in Release file /var/lib/apt/lists/dl.google.com_linux_earth_deb_dists_stable_Release which is considered strong enough for security purposes, E:Failed to fetch http://au.archive.ubuntu.com/ubuntu/dists/trusty-updates/universe/source/Sources.bz2 Hash Sum mismatch, E:Failed to fetch http://au.archive.ubuntu.com/ubuntu/dists/trusty-updates/main/binary-amd64/Packages.bz2 Hash Sum mismatch, E:Failed to fetch http://au.archive.ubuntu.com/ubuntu/dists/trusty-updates/main/binary-i386/Packages.bz2 Hash Sum mismatch, E:Failed to fetch http://au.archive.ubuntu.com/ubuntu/dists/trusty-updates/universe/binary-amd64/Packages.bz2 Hash Su...

This bug was fixed in the package metacity - 1:3.18.4-1ubuntu1

---------------
metacity (1:3.18.4-1ubuntu1) yakkety; urgency=medium

  * Merge with Debian unstable, remaining changes:
    - debian/metacity-common.links: Show keybindings in Unity control center.
    - debian/metacity-common.gsettings-override: Change the default theme to
      Ambiance.
  * Drop all patches, applied upstream.
  * The new release fixes LP: #1566157, #1573478.

 -- Dmitry Shachnev <email address hidden> Tue, 26 Apr 2016 14:21:16 +0300

I've installed it, but it's not convenient today to logout to restart metacity.

Note that the problem with the undisplayable firefox window is probably a separate bug. I think it relates to a similar problem: I keep an xcb window at the bottom of the left screen. It has started vanishing off-screen, too. From the animations if I hide and unhide it, it appears to have dropped below the edge of the displayable area. I'm not sure what triggers it. (I thought perhaps it happens when the scfreen locks, but I just tried that and it doesn't.)

But for xcb, if I select Maximise from the dock menu for it, I can see it and use it. But there's no other way to move its window or resize it so it's back on screen. I have to kill it and restart it. If I start a fresh xcb before killing the old one, it even preserves all the cut buffers.

I've also seen firefox windows lose all their desktop decorations (re-sizing edges, top bar with minimise, maximise, close icons), but hiding and then unhiding it via the window's right-click menu in the dock reinstates all those parts of the window.

I'm also affected by this bug. When will the ubuntu archive include the fix?
Can I download/install the fix without having to wait for metacity 3.18.4 to be officially released in Ubuntu archives?

Thanks

@Francesco Monotrsi
To install metacity from proposed you could follow following instruction
https://wiki.ubuntu.com/Testing/EnableProposed

Unfortunately the place where could be enabled proposed archives was changed a little bit in Ubuntu 16.04.

@Bartosz Kosiorek (gang65)
Thanks for the link. I managed to install the updated metacity package from:
   https://launchpad.net/ubuntu/+source/metacity/1:3.18.4-0ubuntu0.1

and I can confirm that it fixes this bug. I've been using it for a couple of days without troubles, while previously metacity was crashing every 2-3 minutes... I think urgency of this updated package should be increased!

Thanks for the great job

Marking as verification-done according to comment 18.

This bug was fixed in the package metacity - 1:3.18.4-0ubuntu0.1

---------------
metacity (1:3.18.4-0ubuntu0.1) xenial; urgency=medium

  * New upstream bugfix release.
    - Fixes crashes (LP: #1573478).
    - Fixes performance regressions (LP: #1566157).
  * Drop both patches, applied upstream.

 -- Dmitry Shachnev <email address hidden> Sun, 24 Apr 2016 21:37:01 +0300

The verification of the Stable Release Update for metacity has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.