$ mcview -b /lib/x86_64-linux-gnu/libudev.so.1 
/lib/x86_64-linux-gnu/libudev.so.1: symbolic link to libudev.so.1.6.3
0000000000000000 A LIBUDEV_183
0000000000000000 A LIBUDEV_189
0000000000000000 A LIBUDEV_196
0000000000000000 A LIBUDEV_199
0000000000000000 A LIBUDEV_215
0000000000000000 A LIBUDEV_247

$ less /var//log/Xorg.0.log
.
[   458.417] (II) Loading /usr/lib/xorg/modules/input/libinput_drv.so
[   458.418] (EE) Failed to load /usr/lib/xorg/modules/input/libinput_drv.so: /lib/x86_64-linux-gnu/libudev.so.1: version `LIBUDEV_247' not found (required by /usr/lib/x86_64-linux-gnu/libgudev-1.0.so.0)
[   458.418] (EE) Failed to load module "libinput" (loader failed, 0)
[   458.418] (EE) No input driver matching `libinput'

 $ sudo apt policy libgudev-1.0-0
libgudev-1.0-0:
  Installed: 238-2
  Candidate: 238-2
  Version table:
 *** 238-2 100
        100 http://deb.devuan.org/merged ceres/main amd64 Packages
        100 /var/lib/dpkg/status

 deb http://deb.devuan.org/merged/ testing contrib non-free main non-free-firmware 
 deb http://deb.devuan.org/merged/ testing-updates contrib non-free main non-free-firmware
 deb http://deb.devuan.org/merged/ testing-security contrib non-free main non-free-firmware

# apt update

# apt policy libgudev-1.0-0
libgudev-1.0-0:
  Installed: 238-2
  Candidate: 238-2
  Version table:
 *** 238-2 100
        100 http://deb.devuan.org/merged ceres/main amd64 Packages
        100 /var/lib/dpkg/status
     237-2 500
        500 http://deb.devuan.org/merged testing/main amd64 Packages

$ sudo apt install libgudev-1.0-0/testing
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Selected version '237-2' (Devuan:5.0/testing [amd64]) for 'libgudev-1.0-0'
The following packages were automatically installed and are no longer required:
  libavdevice59 libavfilter8 libpostproc56
Use 'sudo apt autoremove' to remove them.
The following packages will be DOWNGRADED:
  libgudev-1.0-0
0 upgraded, 0 newly installed, 1 downgraded, 0 to remove and 40 not upgraded.
Need to get 0 B/15.1 kB of archives.
After this operation, 1,024 B of additional disk space will be used.
Do you want to continue? [Y/n] 
dpkg: warning: downgrading libgudev-1.0-0:amd64 from 238-2 to 237-2
(Reading database ... 371412 files and directories currently installed.)
Preparing to unpack .../libgudev-1.0-0_237-2_amd64.deb ...
Unpacking libgudev-1.0-0:amd64 (237-2) over (238-2) ...
Setting up libgudev-1.0-0:amd64 (237-2) ...
Processing triggers for libc-bin (2.37-6) ...

$ sudo service slim restart
Stopping X display manager: slim.
Starting slim: slim.

rd@beanz:~$ dpkg -l | grep libgudev
ii  libgudev-1.0-0:amd64                           238-2                                  amd64        GObject-based wrapper library for libudev

rd@beanz:~$ sudo apt install libgudev-1.0-0=237-2
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Package libgudev-1.0-0 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Version '237-2' for 'libgudev-1.0-0' was not found

rd@beanz:~$ sudo apt remove libgudev-1.0-0
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 libinput10 : Depends: libwacom9 (>= 2.0.0) but it is not going to be installed
              Depends: libinput-bin (>= 1.23.0-2) but it is not going to be installed
 libqt5svg5 : Depends: libqt5widgets5 (>= 5.15.10+dfsg~) but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

$ head -50 /usr/bin/startxfce4
#!/bin/sh
#
#  xfce4
#
#  Copyright (C) 1996-2003 Olivier Fourdan (fourdan@xfce.org)
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#

if test "x$*" != "x"
then
  OPTS=""
  for OPT in $*
  do
    if test "x$OPT" = "x--help"
    then
      # print help and exit
      echo "Usage:"
      echo "  startxfce4 [OPTIONS...]"
      echo
      echo "Options:"
      echo "  --help                   Show help options"
      echo "  --with-ck-launch         Start xfce4-session inside a"
      echo "                           ConsoleKit session"
      echo

      exit 0
    elif test "x$OPT" = "x--with-ck-launch"
    then
      # try to launch xfce4-session with ck-launch-session in xinitrc
      XFCE4_SESSION_WITH_CK="1"
      export XFCE4_SESSION_WITH_CK
    else
      # append
      OPTS="$OPTS $OPT"
    fi
  done