You're running into the metapackage problem. When you install a metapackage like task-mate-desktop, it pulls in everything you might need for a complete dekstop environement, and when you try to remove a piece of that DE, it breaks the metapackage, which wants to remove ALL of its deps. There are a couple of ways around this, but they both involve starting out with a small installation and adding pieces instead of starting big and removing pieces. When you get to the tasksel window in the installer, un-check the destkop environment box. (maybe un-check everything except standard system utilities.

Then start installing what you want. You could install the mate metapackage, and that would be tied to fewer dependencies than the task- package. Or better yet, install mate-core, see what that brings in, and then start adding other pieces that you need. This way takes a little more work to find what you want, but it makes it a lot easier if you want to remove something.

These might help:

apt-cache rdepends exim4
aptitude why exim4

I think I suggested checking the debian wiki for the graphics drivers. I did not suggest using debian sources.

DO NOT USE DEBIAN OR UBUNTU SOURCES IN YOUR sources.list file.

https://wiki.debian.org/AtiHowTo
https://wiki.debian.org/ATIProprietary

deb http://deb.devuan.org/merged ascii main contrib non-free

For all those ubuntu packages, just remove 'unbuntu' from the name and install it. For example, instead of installing libreoffice-ubuntu from the ppa, install libreoffice from the devuan repository. Do the same with the other packages.

I don't know. Last time I built a heads iso was a year ago. Last time I built a plain devuan iso with live-sdk was a couple weeks ago.

Are you getting any error messages on-screen or in the logs? Is it creating an iso that doesn't work, or not making an iso at all? Is filesystem.squashfs getting created? (look in live-sdk/tmp/devuan-whatever/binary/live/)

You have ascii and ascii-security in your sources. You could add ascii-updates.

The deb-src lines are for source packages. Unless you're planning on creating .deb packages, you can comment those lines.

The problem with synaptic (and gparted and just about anything else that requires root privileges) is that pkexec is broken. One workaround as mentioned above is to start it from a terminal as root. Another option is to edit the .desktop file so it runs a different command. Change the line that has 'Exec=synaptic-pkexec' to one of the following.

Exec=gksu synaptic
or
Exec=xterm -e 'su -c synaptic'

or replace xterm with your favorite terminal.

Note: you don't need to be in the sudo group to use gksu.
Note2: if you are in the sudo group, synaptic might work from the menu without editing the .desktop file. (It did for me in a test install.)

You would need to create your own signing key. Search for 'secure boot self-signed' or something like that, and you'll find instructions.

When the repos were new, backports had the wrong priority. That's been fixed. Twice. Once for packages.devuan.org and then once for pkgmaster.devuan.org. I don't know what the setting is in the repo, but apparently, it's possible to make a mistake. I like to keep backports pinned or disabled (commented out in sources.list), just in case.

If you want to check the priorities of whatever repos you have enabled, run

apt-cache policy

without any package name.

Obviously, something has changed. I can confirm that it now works. I had to do a few things to get it to work...

- removed xserver-xorg-legacy
- disbled my display manager (lxdm)
- tried startx, it wouldn't start.

- added elogind
- still wouldn't start.

-tried it with lxdm. xorg and lxdm are running as root.

- added libpolkit-gobject-1-0-elogind and libpolkit-backend-1-0-elogind, which also pulled in libpam-elogind.
- startx works, and everything is running as user.

- tried it with lxdm again. xorg and lxdm run as root.
- tried it with lightdm. xorg and lightdm run as root.

Here's what I used for sources.list. No pinning, no defualt release defined. This should be enough.

deb http://pkgmaster.devuan.org/merged beowulf main contrib non-free

deb http://pkgmaster.devuan.org/merged ascii main contrib non-free
deb http://pkgmaster.devuan.org/merged ascii-updates main contrib non-free
deb http://pkgmaster.devuan.org/merged ascii-security main contrib non-free

Here are the only installed packages with 'power' in the name or description:

ii  pm-utils                          1.4.1-17                          all          utilities and scripts for power management
ii  powermgmt-base                    1.31+nmu1                         all          Common utils and configs for power management

"no kit" = no consolekit, policykit, libpolkit. I'm not relying on desktop menu entries for shutdown/reboot. I don't know if you lost any of those in the upgrade. Mine started as a debootstrap install, and I added enough to be able to function in a graphical environment. Similar to miyo or vuu-do, but not exactly the same. Compare your before and after package lists to see what you lost. Maybe something can be put back from ascii.

An easy way to keep a log of your changes is to tee the output to a file. Something like:

apt-get upgrade | tee upgrade-log

That way, if you run into some kind of dependency labyrinth, you can share the log to get some possibly useful help.

Things may change a lot over the next few weeks as some key packages in beowulf are rebuilt.

One important point on my smooth upgrade - I did not disable ascii repos, I just added the beowulf repo (singular) and ran an update, upgrade and dist-upgrade. At one point I had to use aptitude to give me some options. 46 out of almost 900 packages did not get upgraded.

That was on a small install with openbox, lxpanel and spacefm. No 'kits. I use sudo for shutdown and pmount for removable drives (with spacefm). Point is, if you don't have a bloated desktop environment, you should be pretty safe. Still, you should be prepared to hose the system and have to start over a few times. Each iteration will be better.

Here are some notes I made for a recent test iso with a newer version of the cli installer. Most of this information applies to the graphical installer, too. Options are mostly controlled in the options window instead of the config file. The parts that talk about which grub is installed and which grub packages are supplied in the iso will only apply if you have those versions of grub installed or available.

You could start with a minimal install and add packages from the parrot package list, configure everything the way you want. It won't be parrotsec, it would be stanzsec. Or, you could do a minimal install and then use 'dpkg --set-selections...' on the parrot package list to reproduce the system. You'd need to remove any unavailable or unwanted packages from the list first.

It might be possible to convert a parrot install to devuan once beowulf is usable. I just checked the package list, and almost everything seems to be in the devuan repositories. Here's a list of packages in parrot that are not in the devuan repos. Some of them you don't want (systemd) and some of them are replaced by other packages (firefox-esr instead of firefox, dbus-x11 instead of dbus-user-session, gnupg in ascii vs. gpg in buster/beowulf, live-config-sysvinit instead of live-config-systemd).

clang-4.0
couchdb
dbus-user-session
firefox
gpg
gpg-agent
iio-sensor-proxy
libegl1
libgl1
libgles2
libglvnd0
libglx0
libopengl0
libpam-systemd
libtesseract4
live-config-systemd
mate-power-manager
pyrit
python-pymssql
spike
systemd
systemd-sysv
torbrowser-launcher
wifite