Ran 'do-release-upgrade' and now TigerVNC won't run....

[Bo Berglund]

On Mon, 13 Mar 2023 14:53:54 +0100, Bo Berglund <bo.berglund at gmail.com> wrote:

>I have an HP Elitebook 8440w, which was running Ubuntu 20.04.5 LTS with the MATE
>desktop.
>It is operated headless, i.e. I have no external monitor attached but use VNC to
>interact with the desktop (pretty seldom). VNC is implemented by TigerVNc
>installed like this:
>sudo apt install tigervnc-standalone-server
>
>It has been working fine for a long time including VNC.
>
>On this I tested the 'do-release-upgrade' command to move to 22.04 and it seemed
>to have worked except when I try to connect VNC it won't.
>
>So I checked the system and found that the conf file had been renamed by the
>upgrade, so I renamed it back and checked the content against my notes - OK.
>Likewise the ~/.vnc/xstartup file looks like it should according to old notes.
>
>Tried starting it:
>
>$ sudo systemctl start vncserver at 1.service
>Job for vncserver at 1.service failed because the control process exited with error
>code.
>See "systemctl status vncserver at 1.service" and "journalctl -xeu
>vncserver at 1.service" for details.

<snip>

I have tried a number of times to update/upgrade and reboot etc but no joy...
The local logfile inside ~/.vnc shows this from the last start attempt:
Command:
$ vncserver :1

Log file entrise:

Mon Mar 13 17:46:02 2023
 vncext:      VNC extension running!
 vncext:      Listening for VNC connections on local interface(s), port 5901
 vncext:      created VNC server for screen 0
3NI3X0 New Xtigervnc server 'polaris-ubuntu:1 (bosse)' on port 5901 for display
:1.
3NI3X0 Use xtigervncviewer -SecurityTypes VncAuth -passwd
/home/bosse/.vnc/passwd :1 to connect to the VNC server.
[mi] mieq: warning: overriding existing handler (nil) with 0x563e04dd9400 for
event 2
[mi] mieq: warning: overriding existing handler (nil) with 0x563e04dd9400 for
event 3
 ComparingUpdateTracker: 0 pixels in / 0 pixels out
 ComparingUpdateTracker: (1:-nan ratio)
vncconfig: unable to open display ":1"
/usr/bin/x-terminal-emulator: Requested to be used as a login shell, but it's
not supported
libmutter-Message: 17:46:02.534: Running Mutter (using mutter 42.5) as a X11
window and compositing manager

** (mate-session:17175): WARNING **: 17:46:02.543: Cannot open display:
Failed to setup: Unable to open display ':1'


Then I tried starting the service instead: 

$ sudo systemctl start vncserver at 1

and found these log lines:

-----------------------------------
Mon Mar 13 17:58:23 2023
 vncext:      VNC extension running!
 vncext:      Listening for VNC connections on all interface(s), port 5901
 vncext:      created VNC server for screen 0
3NI3X0 New Xtigervnc server 'polaris-ubuntu:1 (bosse)' on port 5901 for display
:1.
3NI3X0 Use xtigervncviewer -SecurityTypes VncAuth,TLSVnc -passwd
/home/bosse/.vnc/passwd polaris-ubuntu:1 to connect to the VNC server.
[mi] mieq: warning: overriding existing handler (nil) with 0x55f530bca400 for
event 2
[mi] mieq: warning: overriding existing handler (nil) with 0x55f530bca400 for
event 3
 ComparingUpdateTracker: 0 pixels in / 0 pixels out
 ComparingUpdateTracker: (1:-nan ratio)
vncconfig: unable to open display ":1"
/usr/bin/x-terminal-emulator: Requested to be used as a login shell, but it's
not supported
libmutter-Message: 17:58:23.512: Running Mutter (using mutter 42.5) as a X11
window and compositing manager

** (mate-session:41031): WARNING **: 17:58:23.522: Cannot open display:
Failed to setup: Unable to open display ':1'
--------------------------------------


What exactly should be changed from what I had on Ubuntu 20.04???
What is the problem with the display, isn't it supposed to create a virtual
display when one uses argument :1???


-- 
Bo Berglund
Developer in Sweden