[focal] desktopfolder background is solid black

[John Collins]

Hi I'm running Ubuntu 20.4 with the Apr 20 updates applied.

gnome-session:
  Installed: (none)
  Candidate: 3.36.0-2ubuntu1
  Version table:
     3.36.0-2ubuntu1 500
        500 http://gb.archive.ubuntu.com/ubuntu focal/universe amd64 Packages
        500 http://gb.archive.ubuntu.com/ubuntu focal/universe i386 Packages
gnome-shell:
  Installed: 3.36.9-0ubuntu0.20.04.2
  Candidate: 3.36.9-0ubuntu0.20.04.2
  Version table:
 *** 3.36.9-0ubuntu0.20.04.2 500
        500 http://gb.archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     3.36.4-1ubuntu1~20.04.2 500
        500 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages
     3.36.1-5ubuntu1 500
        500 http://gb.archive.ubuntu.com/ubuntu focal/main amd64 Packages

I accept that this is "cosmetic" but it's still annoying.

I have two large monitors attached which I run as a large single workspace across both screens.

I have been running this for years without problem over several Ubuntu releases.

Following the recent upgrade (Apr 20 2022), my desktop wallpaper is no longer displayed properly.

Almost all of it is covered in solid black except for a very small sliver of the wallpaper at the bottom of each screen.

If I change the desktop background there is no effect (except for the small sliver at the bottom of the screen) changes.

If I reboot, or if I log in as a different user, there is no change.

If I click "Activities" or press the Windows button, the menu of desktops I can switch to is displayed with the correct wallpaper, but when I switch to it it comes out all black on both screens (apart from the icons, any windows and the sliver at the bottom of the screen).

I have 2 different laptops which I have upgraded also but those are OK. I've not tried any dual-screen on them.

Possibly relevant is that I have an nVidia display controller.

It does appear to be a problem that has crept in with the most recent update.

Everything else I do is unaffected as far as I can see but I'd just like something different from the boring solid black.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: ubuntu-release-upgrader-core 1:20.04.37
ProcVersionSignature: Ubuntu 5.13.0-40.45~20.04.1-generic 5.13.19
Uname: Linux 5.13.0-40-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.23
Architecture: amd64
CasperMD5CheckResult: skip
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Sun Apr 24 22:47:59 2022
InstallationDate: Installed on 2020-10-10 (561 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
Symptom: dist-upgrade
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.default.apport: [modified]
mtime.conffile..etc.default.apport: 2020-10-10T15:40:13.152625

[Daniel van Vugt (vanvugt)]

Thanks for the bug report.

My first reaction would be to blame bug 1876632, but if you've not put the machine to sleep then it's unlikely to be bug 1876632.

The screenshot in comment #1 does show some thin sections of wallpaper at the bottom and right edges, so it seems the problem here is just the desktop icons window has become opaque somehow. You should be able to test that by opening the Extensions app and disabling Desktop Icons.

The same issue affects the new Desktop Icons NG extension too: https://gitlab.com/rastersoft/desktop-icons-ng/-/issues/211

[John Collins (johnwgc)]

I just tried disabling the desktop icons and nothing happened (and the icons didn't get disabled either).

[Daniel van Vugt (vanvugt)]

Come to think of it, I would only expect that bug in Desktop Icons NG, not in Desktop Icons.

[Daniel van Vugt (vanvugt)]

Please run:

  journalctl -b0 > journal.txt
  gsettings list-recursively org.gnome.shell > shell-settings.txt
  dpkg -l > packages.txt

and attach the resulting text files here.

[John Collins (johnwgc)]

Here they are

[John Collins (johnwgc)]

Sorry that only seems to be the journal here are the shell settings

[John Collins (johnwgc)]

And here are the packages

[John Collins (johnwgc)]

I noticed the journal had lots of references to /home/jmc/Pictures/2020/03/p16/20200316_064312.jpg which had permissions turned off it was downloaded from my phone as you can see it was over 2 years ago, don't know why it was referenced at all or why the permissions were set to rw-r----- it isn't the photo I've (tried to) set as background.

I've reset the permissions on that file to make them world-readable anyhow but that hasn't changed anything that I can see.

[Daniel van Vugt (vanvugt)]

OK so it really is the old (correct) desktop-icons extension in use. That seems like the most likely explanation still.

I think comment #3 needs another attempt and more investigation because we need to know if disabling the extension fixes it. Please try:

  gsettings set org.gnome.shell disabled-extensions "['desktop-icons@csoriano']"

and if it doesn't work immediately then log in again.

If that still doesn't succeed in removing the icons then please run:

  cd ~/.local/share/gnome-shell
  rm -rf extensions

and log in again.

[Daniel van Vugt (vanvugt)]

Also to find out what is using that jpg file please run:

  gsettings list-recursively | grep 20200316_064312

and paste the output here.

[John Collins (johnwgc)]

Looking at your second answer first, I tried the "gsettings list-recursively ..." but it didn't give any output. That might be because I'd previously fixed the file to be world-readable after I'd noticed the messages in the journal.

I've tried turning off world-readability but the messages haven't reappeared. Seems like whatever was trying to access the file has been satisfied when I let it read the file.

[John Collins (johnwgc)]

Well I tried doing all that with disabling the icons.

It does remove the icons, but the background is still overlaid with opaque black.

It didn't do anything immediately but it did after I logged in - just removed the icons. The directory ~/.local/share/gnome-shell/extensions wasn't there. Mind you it isn't there on a "virgninal" laptop which I haven't done any such fiddling on.

How do I get the icons back though? gseettings reset org. (etc etc) runs OK logged out and back in but no sign of them..... Just empty blackness...

HOWEVER doing that did solve the mystery of the jpg file. Yonks ago I had tried to set that file as a background to the login screen but it didn't work and I gave up, thinking that the instructions on Ubuntu help weren't working but it was ultra-cosmetic and I didn't bother (I leave my machine running and logged in 24/7 and without screen lock - which incidentally is working OK and safe as only myself and GF can get to it).

But doing all that setting that file to be world-readable made it pop up as the background to the login screen. (Such a beautiful picture, sunrise over a sea port, just struck lucky in the early morning. Totally irrelevant but I'll post if if people want to see it.)

It's clearly some weird opacity in the desktop display because if I click "Activities" or press the Windows button I can see my background image appearing hazily with a black mist and reduced-sized windows over it as well as the desktop selection list again showing the background image. But if I select a desktop, the background picture flashes up for a second and then goes black apart from the "sliver" at the bottom.

[John Collins (johnwgc)]

If pictures are worth 1000 words here is what happens if I press the wondows button on the screen I had until I first started typing this. You can see the background image and the destop menus and FB in my other screen.

[Daniel van Vugt (vanvugt)]

Yes the login screen runs as a different user so it can't access your private files until you make them world-readable.

What gets me about this bug is that the black rectangle has nicely rounded corners, like an app window or a zombie splash screen from some app.

If you run 'xwininfo' and then click on the black area, what does it output?

[Daniel van Vugt (vanvugt)]

Have you tried closing all apps? Or log in again, ensuring no apps are started automatically?

[John Collins (johnwgc)]

I've created another user with no applications running at all and still have the desktop covered in black.

I have tried running xwininfo and get the display I attach.

[Daniel van Vugt (vanvugt)]

Please run 'xwininfo' in a Terminal, then click on the black area, and then copy and paste all the text from the Terminal window.

[John Collins (johnwgc)]

xwininfo: Please select the window about which you
          would like information by clicking the
          mouse in that window.

xwininfo: Window id: 0x2000003 (has no name)

  Absolute upper-left X: -10
  Absolute upper-left Y: -10
  Relative upper-left X: -10
  Relative upper-left Y: -10
  Width: 5134
  Height: 1455
  Depth: 32
  Visual: 0xc2
  Visual Class: TrueColor
  Border width: 0
  Class: InputOutput
  Colormap: 0x2000002 (not installed)
  Bit Gravity State: NorthWestGravity
  Window Gravity State: NorthWestGravity
  Backing Store State: NotUseful
  Save Under State: no
  Map State: IsViewable
  Override Redirect State: no
  Corners: +-10+-10 --4+-10 --4--5 +-10--5
  -geometry 5134x1455--4--5

[Daniel van Vugt (vanvugt)]

Thanks, now we just need to figure out who owns window 0x2000003.

Assuming you haven't logged out yet, please run:

  xrestop -b > xrestop.txt

and attach the resulting text file here.

You should also be able to find out which process owns the black window with:

  xprop -id 0x2000003 | grep _NET_WM_PID

[John Collins (johnwgc)]

The second command says

_NET_WM_PID(CARDINAL) = 2554

The xrestop command is still running, having built up to 1.5MB at the time of writing. I'll gzip it and attach it when it's done.

[Daniel van Vugt (vanvugt)]

What process is 2554?

[Daniel van Vugt (vanvugt)]

Also xrestop shouldn't still be running. Perhaps try:

  xrestop -b -m 1 > xrestop.txt

[John Collins (johnwgc)]

Oh gosh it's still going strong having reached 8.5MB can I send you selected highlights as I should imagine 99% of it is going to be irrelevant.

[John Collins (johnwgc)]

Process 2554 is "desktopfolder" which I suppose isn't a surprise.

The original xrestop command was still running, having built up to 11MB. I aborted it and ran it again as you said.

I attach the output from the second xrestop command.

[Daniel van Vugt (vanvugt)]

The problem then is in 'desktopfolder', also tracking in https://github.com/spheras/desktopfolder/issues/312

If you don't need 'desktopfolder' then please uninstall it:

  sudo apt purge desktopfolder

[Daniel van Vugt (vanvugt)]

Ubuntu does not install or support 'desktopfolder'. You can safely remove it, after which you should still have access to your desktop files.

[John Collins (johnwgc)]

Thanks that has completely cured it.

I don't really understand what the command ever did for anyone. Everything I ever do is working fine without it.

Mind you my desktop icons are all over the place now and some had to have launcher re-enabled.

But everything is OK now thanks again.

[John Collins (johnwgc)]

Weird I didn't ever ask for "desktopfolder" to be installed. I must have loaded something else which saw fit to call for it.

But I didn't get any warning messages about XYZ being broken when I removed it.

Thanks again anyhow.