Hello,

The following instructions is the first version of how to migrate from
Debian/Buster to Devuan/Beowulf. This description is a complement to
the description at:
https://www.devuan.org/os/documentation/dev1fanboy/en/buster-to-beowulf
which is known to not work any longer.

Note that this description does use a fixed network interface. For
wireless connections additional tips should be made.

The following text file describes the procedure:
(replacing Debian's gnome desktop (default) with Devuan's mate)

# Choose your editor
apt-get install emacs

Seems like task-gnome-desktop is installed :(
apt-get install sysvinit-core

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer
required: ...
Use 'apt autoremove' to remove them.
The following additional packages will be installed:
  initscripts insserv startpar sysv-rc
The following packages will be REMOVED: ...
The following NEW packages will be installed:
  initscripts insserv startpar sysv-rc sysvinit-core
0 upgraded, 5 newly installed, 34 to remove and 0 not upgraded.
Do you want to continue? [Y/n]
Setting up startpar (0.61-1) ...
Setting up insserv (1.18.0-2) ...
insserv: FATAL: service mountkernfs has to exists for service udev
insserv: FATAL: service urandom has to exists for service networking
insserv: FATAL: service mountdevsubfs has to exists for service hwclock
insserv: exiting now!
Setting up sysv-rc (2.93-8) ...
Setting up initscripts (2.93-8) ...
Setting up sysvinit-core (2.93-8) ...
Not restarting sysvinit

apt-get install task-mate-desktop # No: wants to remove sysvinit-core
<reboot>
Starting system message bus: dbus <times out>
Starting Avahi mDNS <times out>
Starting MTA <times out>
Boots to : No desktop and no network
Log in to console:
apt-get remove --purge libnss-systemd
<reboot> # much faster!!
apt-get remove --purge network-manager
apt-get remove --purge systemd

emacs -nw /etc/network/interfaces
# The primary network interface
auto ens3
iface ens3 inet dhcp
<reboot> # now with network and ssh :)
apt-get install task-{xfce,mate}-desktop
<wants to remove sysvinit-core>

dpkg --set-selections
sysvinit-core hold

apt-get install task-{xfce,mate}-desktop
The following packages have unmet dependencies:
systemd-sysv : Conflicts: sysvinit-core but 2.93-8 is installed
sysvinit-core : Conflicts: systemd-sysv but 241-7~deb10u7 is to be
installed
...

apt-get install lightdm
The following packages have unmet dependencies:
lightdm :
Depends: logind or consolekit but it is not installable

apt-get install lightdm elogind
The following NEW packages will be installed:
elogind libelogind0 libindicator3-7 liblightdm-gobject-1-0 libpam-
elogind lightdm lightdm-gtk-greeter

apt-get install task-mate-desktop
The following packages have unmet dependencies:
task-mate-desktop :
Depends: mate-desktop-environment but it is not going to be installed
Depends: lightdm but it is not going to be installed
<seems difficult to get a desktop working in Debian, giving up>

emacs /etc/apt/sources.list
deb http://deb.devuan.org/merged beowulf main
deb http://deb.devuan.org/merged beowulf-security main
deb http://deb.devuan.org/merged beowulf-updates main
deb http://deb.devuan.org/devuan beowulf-proposed main

wget
https://pkgmaster.devuan.org/devuan/pool/main/d/devuan-keyring/devuan-keyring_2017.10.03_all.deb
dpkg -i devuan-keyring_2017.10.03_all.deb
apt-get update
apt-get upgrade
The following packages will be upgraded:
base-files bsdutils colord-data dbus dbus-x11 distro-info-data fdisk
gir1.2-packagekitglib-1.0 init init-system-helpers initscripts
libblkid1 libcolorhug2 libdbus-1-3 libfdisk1 liblightdm-gobject-1-0
libmount1 libpackagekit-glib2-18 libpcsclite1 libprocps7 libsmartcols1
libudisks2-0 libuuid1 lightdm mount procps python3-reportbug reportbug
rsyslog sysv-rc sysvinit-utils task-british-desktop task-desktop task-
english task-ssh-server tasksel tasksel-data util-linux-locales

apt-get autoremove --purge
dpkg --set-selections
sysvinit-core install
The following packages have been kept back:
desktop-base elogind libcolord2 libelogind0 libpam-elogind
libpolkit-gobject-1-0 libudev1 udev util-linux
The following packages will be upgraded:
sysvinit-core
apt-get dist-upgrade
The following NEW packages will be installed:
cinnabar-icon-theme clearlooks-phenix-cinnabar-theme dmz-cursor-theme
eudev gnome-extra-icons gnome-icon-theme gtk2-engines gtk3-
nooverlayscrollbar libeudev1 libpolkit-gobject-elogind-1-0
The following packages have been kept back:
elogind libelogind0 libpam-elogind
The following packages will be upgraded:
desktop-base libcolord2 libpolkit-gobject-1-0 libudev1 udev util-
linux

apt-get dist-upgrade
apt-get install net-tools
ifconfig
ens3: ...
lo: ...
<reboot>

Booting into Devuan :)
No desktop at all. Boot into recovery mode.
emacs -nw /etc/network/interfaces
#auto ens3
#iface ens3 inet dhcp
auto eth0
iface eth0 inet dhcp
/etc/init.d/ssh start <ssh works>
apt-get install task-mate-desktop
0 upgraded, 311 newly installed, 0 to remove and 3 not upgraded.

apt-get dist-upgrade
The following packages have been kept back:
elogind libelogind0 libpam-elogind
apt-get install elogind
The following packages will be REMOVED:
libsystemd0
The following packages will be upgraded:
elogind libelogind0 libpam-elogind
The following packages will be REMOVED:
libsystemd0
<reboot>
<login OK to lightdm/mate>