`mate-session` continuously logs ALSA errors

[roy-work]

Note: I am on a virtual machine.

Expected behaviour

Perhaps a one time warning that sound doesn't work, although I didn't think the session manager made sounds?

Now, mate-session spawns a few child processes (for me, that's mate-settings-daemon, marco, mate-panel, caja, and polkit-mate-authentication-agent-1. It could be that I'm seeing the logs of one of the children, through an inherited stdin.

Actual behaviour

mate-session logs the following once per second:

ALSA lib confmisc.c:855:(parse_card) cannot find card '0'
ALSA lib conf.c:5180:(_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:5180:(_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:5180:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:5703:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib control.c:1528:(snd_ctl_open_noupdate) Invalid CTL default

Steps to reproduce the behaviour

• Be on a VM; I presume my VM, by virtue of being a VM, lacks a sound device. (This is a VM in GCP, in my case.)
• Install MATE
• Install TigerVNC
• Start Xvnc; I use, Xvnc -rfbport=-1 -rfbunixpath="$HOME/.vnc/vnc.sock" -SecurityTypes=None :0
• Start mate-session, e.g., DISPLAY=:0 mate-session
• Receive errors.

MATE general version

This also seems to be a bug?

» mate-session --help
Usage:
  mate-session [OPTION…]  - the MATE session manager

Help Options:
  -h, --help                       Show help options
  --help-all                       Show all help options
  --help-gtk                       Show GTK+ Options

Application Options:
  -a, --autostart                  Override standard autostart directories
  --debug                          Enable debugging code
  -f, --failsafe                   Do not load user-specified applications
  --version                        Version of this application
  --disable-acceleration-check     Disable hardware acceleration check
  --display=DISPLAY                X display to use

» mate-session --version

** (mate-session:38430): WARNING **: 18:30:56.220: Cannot open display:
»

Package version

1.26.0-1ubuntu1

Linux Distribution

Ubuntu 23.04 ("lunar")

Link to bugreport of your Distribution (requirement)

[zhuyaliang]

This is not a matter of mate-session, it seems to be a problem with pulseaudio. The mate-session is responsible for starting the application programs in /etc/xdg/autostart/, which should include pulseaudio

[zhuyaliang]

@roy-work Can I close the issue ？

[roy-work]

I don't think this is pulseaudio; it doesn't appear to be running:

» ps -ef | grep pulse
roy      1378756 1378374  0 20:55 pts/15   00:00:00 grep --color pulse

It doesn't seem like pulseaudio is included in /etc/xdg/autostart:

» ls -l
total 28
-rw-r--r-- 1 root root  193 Mar 27  2023 at-spi-dbus-bus.desktop
-rw-r--r-- 1 root root  165 Mar 20  2023 im-launch.desktop
-rw-r--r-- 1 root root 3190 Apr  8  2022 mate-settings-daemon.desktop
-rw-r--r-- 1 root root 7796 Oct 16  2022 polkit-mate-authentication-agent-1.desktop
-rw-r--r-- 1 root root  228 May 29 05:45 snap-userd-autostart.desktop
-rw-r--r-- 1 root root  250 Sep 26  2022 xdg-user-dirs.desktop

The pulseaudio Ubuntu package isn't installed on this VM, so I don't think it even has pulseaudio.

(It doesn't seem like there's a sound daemon in that directory on a separate machine I have that's a normal — i.e., physical — machine, either.)

[zhuyaliang]

Check if mate-volume-control-applet is started
Anyway, this is not mate-session-manage issue. This issue was caused by alsa-lib and may have been caused by an incorrect configuration

[roy-work]

Check if mate-volume-control-applet is started

It is not. Should it have been / what chain of events is supposed to start it?