gnome-control-centre crashes after enabling "Sharing"

[David JM Emmett]

Impact
------
gnome-control-center uses gsettings schemas from the gnome-remote-desktop package without being able to handle if those schemas are not installed.

Because gnome-control-center keeps track of which page was last opened, it's not possible to simply ignore the Sharing page, a user would need to manually open the Settings app to a different page or else the Settings app won't run at all.

ubuntu-desktop and gnome-shell already Recommend gnome-remote-desktop so most people won't experience this issue.

Test Case
---------
sudo apt remove gnome-remote-desktop
Run gnome-control-center
From the left sidebar, click Sharing
(The app crashes)
Install the update. The update will install gnome-remote-desktop.
Run gnome-control-center
The app should work like normal

What Could Go Wrong
-------------------
This only adds a hard dependency on gnome-remote-desktop.

Without this fix, the Sharing panel didn't work at all.

Original Bug Report
-------------------
After the crash, gnome-control-centre fails to launch again.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: gnome-control-center 1:41.7-0ubuntu0.22.04.1
ProcVersionSignature: Ubuntu 5.15.0-40.43-generic 5.15.35
Uname: Linux 5.15.0-40-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu82.1
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: GNOME
Date: Sun Jul 3 20:39:04 2022
InstallationDate: Installed on 2017-05-24 (1866 days ago)
InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
SourcePackage: gnome-control-center
UpgradeStatus: Upgraded to jammy on 2022-05-31 (33 days ago)

[David JM Emmett (davidjmemmett)]

Looks like the logs that apport-bug uploaded didn't include the syslog. Please find the relevant statements below:

```
david@polar:~$ grep gnome-control-c /var/log/syslog
...
Jul 3 20:38:11 polar gnome-control-c[11235]: Settings schema 'org.gnome.desktop.remote-desktop.vnc' does not contain a key named 'enable'
Jul 3 20:38:11 polar kernel: [ 699.349484] traps: gnome-control-c[11235] trap int3 ip:7f7a5281eccf sp:7ffdf1107bf0 error:0 in libglib-2.0.so.0.7200.1[7f7a527df000+8f000]
...
Jul 3 21:41:10 polar gnome-control-c[20800]: Settings schema 'org.gnome.desktop.remote-desktop.vnc' does not contain a key named 'enable'
Jul 3 21:41:10 polar kernel: [ 4477.717988] traps: gnome-control-c[20800] trap int3 ip:7f2dcd744ccf sp:7fffe09c1de0 error:0 in libglib-2.0.so.0.7200.1[7f2dcd705000+8f000]

```

[Jeremy Bícha (jbicha)]

What version of gsettings-desktop-schemas do you have installed?

[Jeremy Bícha (jbicha)]

The most likely reason for you to get that error [1] is that you don't have gsettings-desktop-schemas 42 installed.

[1] Settings schema 'org.gnome.desktop.remote-desktop.vnc' does not contain a key named 'enable'

[David JM Emmett (davidjmemmett)]

Hi @jbicha,

That would be 42.0-1ubuntu1:

```
$ apt show gsettings-desktop-schemas
Package: gsettings-desktop-schemas
Version: 42.0-1ubuntu1
Priority: optional
...
```

Cheers,
David

Edit: that information is available in the file `Dependencies.txt` uploaded with the original issue report.

[Jeremy Bícha (jbicha)]

Does it fix your problem if you run this command?

sudo apt install gnome-remote-desktop

[David JM Emmett (davidjmemmett)]

Hi @jbicha,

It appears we both responded simultaneously. Given that the crash occurs in gnome-control-centre, I'd suggest that the issue lies there - regardless of whether a key exists in a DB, that is the application that faulted and fails to re-open afterwards.

Cheers,
David

[David JM Emmett (davidjmemmett)]

Hi @jbicha,

It looks like gnome-remote-desktop may have been uninstalled during the upgrade to jammy due to conflicts from the remmina-next PPA. I had to manually uninstall a few packages and then was able to reinstall gnome-remote-desktop:

```
david@polar:~$ sudo apt install gnome-remote-desktop
...
The following packages have unmet dependencies.
 libfreerdp-server2-2 : Depends: libfreerdp2-2 (= 2.7.0+git202204251304-0+remmina202205020710.r40ee5d3bc.d776065661~ubuntu22.04.1) but 2.7.0+git202204251304-0+remmina202205020710.r40ee5d3bc.da996883ab~ubuntu20.04.1 is to be installed
```

```
david@polar:~$ sudo apt remove libfreerdp2-2 libvncserver1 libwinpr2-2
...
```

Following this, I was able to successfully install gnome-remote-desktop.

(I know PPAs are unsupported, I'm documenting in case anyone else hits the same issue.)

Thank you for looking into this issue.

Cheers,
David

[Łukasz Zemczak (sil2100)]

It's hard for me to check: is this already released for kinetic? Since the bug status says Fix Committed there.

[Łukasz Zemczak (sil2100)]

Hello David, or anyone else affected,

Accepted gnome-control-center into jammy-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/gnome-control-center/1:41.7-0ubuntu0.22.04.3 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 on 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, what testing has been performed on the package and change the tag from verification-needed-jammy to verification-done-jammy. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-jammy. In either case, without details of your testing we will not be able to proceed.

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

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Steve Langasek (vorlon)]

Hello David, or anyone else affected,

Accepted gnome-control-center into jammy-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/gnome-control-center/1:41.7-0ubuntu0.22.04.4 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 on 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, what testing has been performed on the package and change the tag from verification-needed-jammy to verification-done-jammy. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-jammy. In either case, without details of your testing we will not be able to proceed.

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

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Nathan Teodosio (nteodosio)]

I couldn't get the crash with >gnome-control-center 1:41.7-0ubuntu0.22.04.1<, even though gnome-remote-desktop was not installed, and even after logout/login; After clicking "sharing", in the header there was the toggle button, in the right pane there were the computer name field and the media sharing button.

I verified that I get no crash >gnome-control-center 1:41.7-0ubuntu0.22.04.4<, which also pulls gnome-remote-desktop as a dependency and adds the remote desktop button to the right pane.

[Launchpad Janitor (janitor)]

This bug was fixed in the package gnome-control-center - 1:41.7-0ubuntu0.22.04.4

---------------
gnome-control-center (1:41.7-0ubuntu0.22.04.4) jammy; urgency=medium

  * debian/patches: Read the user value for gedit setting before changing it.
    This is an oversight while backporting the patch that is already in
    kinetic. (LP: #1968213)
  * debian/gbp.conf: Set upstream branch to upstream/42.x

gnome-control-center (1:41.7-0ubuntu0.22.04.3) jammy; urgency=medium

  * debian/control.in: Depend on gnome-remote-desktop (LP: #1980606)

gnome-control-center (1:41.7-0ubuntu0.22.04.2) jammy; urgency=medium

  * debian/patches: Refresh indexes
  * debian/patches: Ensure VNC/RDP remote control setting is honored
    (LP: #1977663)
  * ubuntu-panel: Do not change themes on startup (or on user changes)
    Do not override user themes unless an user has explicitly selected a
    color theme. This applies to both the user theme and the icons, as we
    want a consistent experience. But users could still use tweaks to change
    them.
    At the same time, avoid changing the gedit color scheme if an user
    previously set a non-Yaru theme. (LP: #1968213)

 -- Marco Trevisan (Treviño) <email address hidden> Thu, 11 Aug 2022 16:10:13 -0400

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for gnome-control-center has completed successfully and the package is now being 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.

[wontfix (wontfix)]

Can this also apply to 41 to more equalize dependencies with Kinetic, Lunar, Mantic and above?
https://launchpad.net/ubuntu/+source/gnome-control-center/1:42.3-2ubuntu1