TigerVNC server on Ubuntu 22.04 logs errors - how to block ALSA?

Wed Mar 15 07:14:56 UTC 2023

I have just completed setting up TigerVNC on my Ubuntu 22.04 laptop using
instructions from here:
https://bytexd.com/how-to-install-configure-vnc-server-on-ubuntu/

I am using the RealVNC client on Windows 10 for access.

When I enable the VNC service on my Ubuntu device it starts logging a lot of
errors without even anyone connecting.

The connection itself seems to work fine, though, so I did not see this until I
inspected the ~/.vnc directory on the Linux side.
There is a log file that grows very fast and contains loads of log lines
regarding ALSA.
It starts out as shown below, what can I do to fix it?
I do NOT need audio over VNC at all so I would like to switch off whatever is
causing this.

It goes on-and-on and the file grows very fast.

Start of log:
-------------

Xvnc TigerVNC 1.12.0 - built 2022-03-25 17:06
Copyright (C) 1999-2021 TigerVNC Team and many others (see README.rst)
See https://www.tigervnc.org for information on TigerVNC.
Underlying X server release 12101003, X.Org

Wed Mar 15 08:00:33 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 0x564f1bf3b400 for
event 2
[mi] mieq: warning: overriding existing handler (nil) with 0x564f1bf3b400 for
event 3
mate-session-check-accelerated: GL Helper exited with code 512
mate-session-check-accelerated: GLES Helper exited with code 512
GNOME_KEYRING_CONTROL=/home/bosse/.cache/keyring-Y0Q111
SSH_AUTH_SOCK=/home/bosse/.cache/keyring-Y0Q111/ssh
mate-session[252105]: WARNING: Unable to find provider '' of required component
'dock'
ALSA lib confmisc.c:855:(parse_card) cannot find card '0'
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_card_inum returned
error: No such file or directory
ALSA lib confmisc.c:422:(snd_func_concat) error evaluating strings
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_concat returned
error: No such file or directory
ALSA lib confmisc.c:1334:(snd_func_refer) error evaluating name
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_refer returned
error: No such file or directory
ALSA lib conf.c:5701:(snd_config_expand) Evaluate error: No such file or
directory
ALSA lib control.c:1528:(snd_ctl_open_noupdate) Invalid CTL default

** (mate-settings-daemon:252190): WARNING **: 08:00:33.765: Could not open
RFKILL control device, please verify your installation
Window manager warning: Log level 128: unsetenv() is not thread-safe and should
not be used after threads are created
03/15/23 08:00:34: Getting dock from dconf.
03/15/23 08:00:34: Dock is not set in dconf, doing nothing.
caja-dropbox is not installed, doing nothing.
GNOME_KEYRING_CONTROL=/home/bosse/.cache/keyring-Y0Q111
SSH_AUTH_SOCK=/home/bosse/.cache/keyring-Y0Q111/ssh
mate-session[252105]: WARNING: Could not launch application
'mate-maximus-autostart.desktop': Unable to start application: Failed to execute
child process mate-maximus (No such file or directory)
GNOME_KEYRING_CONTROL=/home/bosse/.cache/keyring-Y0Q111
SSH_AUTH_SOCK=/home/bosse/.cache/keyring-Y0Q111/ssh
....snip....
(process:252586): ayatana-indicator-datetime-WARNING **: 08:00:34.745:
Unrecognized TZID: 'Etc/Utc'
ALSA lib confmisc.c:855:(parse_card) cannot find card '0'
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_card_inum returned
error: No such file or directory
ALSA lib confmisc.c:422:(snd_func_concat) error evaluating strings
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_concat returned
error: No such file or directory
ALSA lib confmisc.c:1334:(snd_func_refer) error evaluating name
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_refer returned
error: No such file or directory
ALSA lib conf.c:5701:(snd_config_expand) Evaluate error: No such file or
directory
ALSA lib control.c:1528:(snd_ctl_open_noupdate) Invalid CTL default
blueman-applet 08.00.35 WARNING  PluginManager:147 __load_plugin: Not loading
PPPSupport because its conflict has higher priority
blueman-applet 08.00.35 WARNING  PluginManager:147 __load_plugin: Not loading
DhcpClient because its conflict has higher priority
Initializing caja-sendto extension
Initializing caja-wallpaper extension
Initializing caja-open-terminal extension
RuntimeError: object at 0x7f2ae8a2a040 of type FolderColorMenu is not
initialized
ALSA lib confmisc.c:855:(parse_card) cannot find card '0'
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_card_inum returned
error: No such file or directory
ALSA lib confmisc.c:422:(snd_func_concat) error evaluating strings
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_concat returned
error: No such file or directory
ALSA lib confmisc.c:1334:(snd_func_refer) error evaluating name
ALSA lib conf.c:5178:(_snd_config_evaluate) function snd_func_refer returned
error: No such file or directory

Then it is all about ALSA...

-- 
Bo Berglund
Developer in Sweden