System:
  Kernel: 6.12.57+deb13-amd64 arch: x86_64 bits: 64 compiler: gcc v: 14.2.0 clocksource: tsc
  Desktop: Cinnamon v: 6.4.10 tk: GTK v: 3.24.49 wm: Muffin v: 6.4.1 vt: 7 dm: LightDM v: 1.32.0
    Distro: Devuan GNU/Linux 6 (excalibur)

The upgrade to Excalibur removed the logviewer I used under Daedalus, the gnome-system-log package. Somebody told me that gnome-logs is the replacement. But this package only takes care for the systemd journal now.

My solution: install mate-utils. That package amongst other stuff contains the mate-system-log.

To make it work also for the syslog and dmesg I had to create a new menu entry. Main topic is the command:

pkexec /usr/bin/mate-system-log

As icon I selected /usr/share/icons/hicolor/48x48/apps/mate-system-log.png which came with the package. 

Also I needed to supply a policy action for policykit. I had one in my backups from previously using Mate as desktop. To be stored in /usr/share/polkit-1/actions as org.mate.mate-system-log.policy. Contents:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE policyconfig PUBLIC
 "-//freedesktop//DTD PolicyKit Policy Configuration 1.0//EN"
 "http://www.freedesktop.org/standards/PolicyKit/1.0/policyconfig.dtd">
<policyconfig>

  <vendor>Mate-System-Log</vendor>
  <vendor_url></vendor_url>
  <icon_name>mate-system-log</icon_name>

<action id="org.mate-system-log.pkexec">
   <description>Run mate-system-log as root</description>
   <message>Authentication is required to run mate-terminal as root.</message>
   <defaults>
      <allow_any>no</allow_any>
      <allow_inactive>auth_admin</allow_inactive>
      <allow_active>auth_admin</allow_active>
   </defaults>
   <annotate key="org.freedesktop.policykit.exec.path">/usr/bin/mate-system-log</annotate>
   <annotate key="org.freedesktop.policykit.exec.allow_gui">true</annotate>
 </action>