can't change MATE panel layout by mate-tweak because of missed mate-volume-control-applet executable

[N0rbert]

Steps to reproduce the issue:

1. Install task-mate-desktop with mate-tweak to get full MATE desktop
2. Launch mate-tweak from terminal
3. Go to Panel tab, then try to switch panel layouts using drop-down menu

Expected results:

• user is able to select any available MATE Panel layouts - one from Fedora,
  GNOME, openSUSE

Actual results:

• user is unable to select needed panel layout, gets the following error
  messages in the terminal:

$ mate-tweak
Window Manager is: marco-no-composite
System installed layouts:
['fedora', 'default', 'opensuse']
Current layout: opensuse
/usr/bin/mate-tweak:684: PyGTKDeprecationWarning: The "buttons" argument must
be a Gtk.ButtonsType enum value. Please use the "add_buttons" method for adding
buttons. See: https://wiki.gnome.org/PyGObject/InitializerDeprecations
  dialog = Gtk.Dialog(title, None, Gtk.DialogFlags.MODAL |
Gtk.DialogFlags.DESTROY_WITH_PARENT,
/usr/bin/mate-tweak:684: PyGTKDeprecationWarning: The "flags" argument for
dialog construction is deprecated. Please use initializer keywords: modal=True
and/or destroy_with_parent=True. See:
https://wiki.gnome.org/PyGObject/InitializerDeprecations
  dialog = Gtk.Dialog(title, None, Gtk.DialogFlags.MODAL |
Gtk.DialogFlags.DESTROY_WITH_PARENT,
/usr/bin/mate-tweak:690: PyGTKDeprecationWarning: Using positional arguments
with the GObject constructor has been deprecated. Please specify keyword(s) for
"label" or use a class specific constructor. See:
https://wiki.gnome.org/PyGObject/InitializerDeprecations
  label = Gtk.Label(text)
Switching to: fedora
Traceback (most recent call last):
  File "/usr/bin/mate-tweak", line 1047, in combo_fallback
    self.additional_tweaks(schema, key, value[1])
  File "/usr/bin/mate-tweak", line 1031, in additional_tweaks
    self.replace_panel_layout(panel_layout)
  File "/usr/bin/mate-tweak", line 768, in replace_panel_layout
    self.enable_applets()
  File "/usr/bin/mate-tweak", line 571, in enable_applets
    pid = subprocess.Popen(['mate-volume-control-applet'], stdout=DEVNULL,
stderr=DEVNULL).pid
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/subprocess.py", line 1024, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/usr/lib/python3.11/subprocess.py", line 1901, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'mate-volume-control-
applet'
/usr/bin/mate-tweak:684: PyGTKDeprecationWarning: The "buttons" argument must
be a Gtk.ButtonsType enum value. Please use the "add_buttons" method for adding
buttons. See: https://wiki.gnome.org/PyGObject/InitializerDeprecations
  dialog = Gtk.Dialog(title, None, Gtk.DialogFlags.MODAL |
Gtk.DialogFlags.DESTROY_WITH_PARENT,
/usr/bin/mate-tweak:684: PyGTKDeprecationWarning: The "flags" argument for
dialog construction is deprecated. Please use initializer keywords: modal=True
and/or destroy_with_parent=True. See:
https://wiki.gnome.org/PyGObject/InitializerDeprecations
  dialog = Gtk.Dialog(title, None, Gtk.DialogFlags.MODAL |
Gtk.DialogFlags.DESTROY_WITH_PARENT,
/usr/bin/mate-tweak:690: PyGTKDeprecationWarning: Using positional arguments
with the GObject constructor has been deprecated. Please specify keyword(s) for
"label" or use a class specific constructor. See:
https://wiki.gnome.org/PyGObject/InitializerDeprecations
  label = Gtk.Label(text)
Switching to: default
Traceback (most recent call last):
  File "/usr/bin/mate-tweak", line 1047, in combo_fallback
    self.additional_tweaks(schema, key, value[1])
  File "/usr/bin/mate-tweak", line 1031, in additional_tweaks
    self.replace_panel_layout(panel_layout)
  File "/usr/bin/mate-tweak", line 768, in replace_panel_layout
    self.enable_applets()
  File "/usr/bin/mate-tweak", line 571, in enable_applets
    pid = subprocess.Popen(['mate-volume-control-applet'], stdout=DEVNULL,
stderr=DEVNULL).pid
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/subprocess.py", line 1024, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/usr/lib/python3.11/subprocess.py", line 1901, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'mate-volume-control-
applet'
/usr/bin/mate-tweak:684: PyGTKDeprecationWarning: The "buttons" argument must
be a Gtk.ButtonsType enum value. Please use the "add_buttons" method for adding
buttons. See: https://wiki.gnome.org/PyGObject/InitializerDeprecations
  dialog = Gtk.Dialog(title, None, Gtk.DialogFlags.MODAL |
Gtk.DialogFlags.DESTROY_WITH_PARENT,
/usr/bin/mate-tweak:684: PyGTKDeprecationWarning: The "flags" argument for
dialog construction is deprecated. Please use initializer keywords: modal=True
and/or destroy_with_parent=True. See:
https://wiki.gnome.org/PyGObject/InitializerDeprecations
  dialog = Gtk.Dialog(title, None, Gtk.DialogFlags.MODAL |
Gtk.DialogFlags.DESTROY_WITH_PARENT,
/usr/bin/mate-tweak:690: PyGTKDeprecationWarning: Using positional arguments
with the GObject constructor has been deprecated. Please specify keyword(s) for
"label" or use a class specific constructor. See:
https://wiki.gnome.org/PyGObject/InitializerDeprecations
  label = Gtk.Label(text)
Switching to: opensuse
Traceback (most recent call last):
  File "/usr/bin/mate-tweak", line 1047, in combo_fallback
    self.additional_tweaks(schema, key, value[1])
  File "/usr/bin/mate-tweak", line 1031, in additional_tweaks
    self.replace_panel_layout(panel_layout)
  File "/usr/bin/mate-tweak", line 768, in replace_panel_layout
    self.enable_applets()
  File "/usr/bin/mate-tweak", line 571, in enable_applets
    pid = subprocess.Popen(['mate-volume-control-applet'], stdout=DEVNULL,
stderr=DEVNULL).pid
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.11/subprocess.py", line 1024, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/usr/lib/python3.11/subprocess.py", line 1901, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'mate-volume-control-
applet'

Please note that Ayatana indicators are not installed.
The same happens on Debian 11 (oldstable, bullseye).

Downstream bug-report: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1043291

[N0rbert]

Technical details about the bug (see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1043291#15 ):

The problem here is caused by mate-volume-control-applet file location.
It came from mate-media, you are right about this package
Problem persists even with the installed mate-media package.
In Debian 10 (buster) it was located in PATH -
/usr/bin/mate-volume-control-applet (see https://packages.debian.org/search?suite=buster&arch=any&mode=path&searchon=contents&keywords=mate-volume-control-applet ).
But in Debian 11 and newer it is located in non-PATH place -
/usr/libexec/mate-volume-control-applet (see https://packages.debian.org/search?suite=bullseye&arch=any&mode=path&searchon=contents&keywords=mate-volume-control-applet ).
So it can't be found by mate-tweak (see https://sources.debian.org/src/mate-tweak/22.10.0-2/mate-tweak/?hl=78#L571 ).

My local quick and dirty hack is the following:

sudo ln -sf /usr/libexec/mate-volume-control-applet /usr/local/bin/mate-volume-control-applet

But I would suggest fixing this problem in the mate-tweak script - for example you can call this applet by full path -
/usr/libexec/mate-volume-control-applet.
It is still applicable for default Debian installation without Ayatana indicators.

[N0rbert]

Actually the bug also exists in OpenSuSe Tumbleweed (tested today using openSUSE-Tumbleweed-NET-x86_64-Snapshot20230823-Media.iso).
Ugly hack for it is the following:

sudo ln -sf /usr/libexec/mate-media/mate-volume-control-applet /usr/local/bin/mate-volume-control-applet

OS details:

$ rpm -qa | grep -E "mate-(media|tweak)" | grep -v lang
mate-media-1.26.1-1.3.x86_64
mate-tweak-22.10.0-1.2.noarch

Other RPM-based distros are probably affected too.

[N0rbert]

Mageia 9 is affected too.
Ugly fix:

sudo ln -sf /usr/libexec/mate-volume-control-applet /usr/local/bin/mate-volume-control-applet

Info:

$ rpm -qa | grep -E "mate-(media|tweak)"
mate-media-1.26.1-1.mga9
mate-tweak-21.04.3-5.mga9

[N0rbert]

On Debian 12 (bookworm) this bug may be fixed by using specially created meta-package named Debian MATE Ayatana Settings - see its README.md for installation instuctions.
This debian-mate-ayatana-settings package contains configuration and default settings for Debian with MATE and Ayatana Indicators.

[cwendling]

It indeed should look in the libexec directory, see https://github.com/mate-desktop/mate-media/blob/master/mate-volume-control/Makefile.am#L116
However, note that this is only true if built out-of-process, if building in-process what is relevant is the presence of the applet's library.