neutrinosteak: if it's a uefi system, this may help:
https://dev1galaxy.org/viewtopic.php?id=2676

Yup it's UEFI. I removed grub-efi-amd64-signed and ran grub-install, and it fixed my system! Thanks for pointing me in the right direction

Be aware you need to run the command boot-update after (re-)installing Grub or replacing a kernel. And you need to run it as root

That won't work so well in debian-based distros. (Won't work at all.)

grub-install [target] installs the bootloader. target is a drive or partition for legacy/bios systems, omitted for uefi systems.
update-grub creates the boot menu

hi, I have upgraded my machine to beowulf. Thanks to all the people for their instructions. My steps.

# apt-get update && apt-get upgrade
Replaced all -ascii- to -beowulf- in /etc/apt/sources.list
Created /etc/apt/preferences.d/avoid_some_beo like fsmithred did.
# apt-get update
# apt-get upgrade
# apt-get dist-upgrade
# reboot

Issues:
firefox 67.0b2 tab crashes while playing any video
no audio in youtube video using vivaldi browser instead of firefox.
fish shell does not work.

Comment out autospawn in /etc/pulse/client.conf.d/00-disable-autospawn.conf fix firefox issues.
uninstall fish
purge fish configuration files and omf configuration files
install fish

I tried this process on a fresh devuan install, and it went fine until I got to the reboot; now it just shows a grub menu with no options. I tried using chroot to run update-grub from an ascii Live-USB, and the update ran fine, it saw the new kernel and didn't throw any errors. But the grub menu is still empty on reboot. Does anyone have insight into what could have gone wrong?

Created /etc/apt/preferences.d/avoid_some_beo like fsmithred did.

It is my understanding that you do not need this any more.  You might want to try to remove it and see what wants to get updated.  Also, if you have them, you may be able to remove all references to ascii from sources.list .  I have done this to a couple of beowulf installs and it has caused no problems.  However, I do have one beowulf install where I still have ascii references in sources.list file so that I can use the ascii version of network-manager and its openvpn tools.

From what I have read and experienced, there have been at least two major improvements recently that makes beowulf closer to a beta state - first, the polkits got a major facelift a few weeks ago which have been applied with your dist-upgrade to beowulf, and second, you can run

apt install libelogind0

and this will make a noticable change to your system.

And may I add that the change produced with libelogind0 was very nice to see... (-;

# apt-get update && apt-get upgrade
Replaced all -ascii- to -beowulf- in /etc/apt/sources.list
Created /etc/apt/preferences.d/avoid_some_beo like fsmithred did.
# apt-get update
# apt-get upgrade
# apt-get dist-upgrade
# reboot

Issues:
firefox 67.0b2 tab crashes while playing any video
no audio in youtube video using vivaldi browser instead of firefox.
fish shell does not work.

Comment out autospawn in /etc/pulse/client.conf.d/00-disable-autospawn.conf fix firefox issues.
uninstall fish
purge fish configuration files and omf configuration files
install fish

I'm really really grateful for making this thread because without this thread I would have had to move to some other distro since I needed some packages from beowulf and after upgrading to beowulf, libpolkit issue arised.

Thanks to you too. Without this post I would have had spent lots of time trying to fix audio because it was working fine with ascii.

The only issue experienced was an issue with minissdpd. It kept failing but I don't need/use it anyways so it was removed!

Here is the /etc/apt/preferences.d/beowulf file I used

Package: policykit-1
Pin: version 0.105-18*
Pin-Priority: 1001

Package: libpolkit-agent-1-0
Pin: version 0.105-18*
Pin-Priority: 1001

Package: libpolkit-backend-1-0
Pin: version 0.105-18*
Pin-Priority: 1001

Package: libpolkit-backend-elogind-1-0
Pin: version 0.105-18*
Pin-Priority: 1001

Package: libpolkit-gobject-1-0
Pin: version 0.105-18*
Pin-Priority: 1001

Package: libpolkit-gobject-elogind-1-0
Pin: version 0.105-18*
Pin-Priority: 1001

From here how could i help devuan using testing?

Added beowulf to sources.list:

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

Created /etc/apt/preferences.d/beowulf with contents from fsmithred's pin:

Then ran apt-get update
Then apt-get dist-upgrade

I had no sound on one of my machines that uses pulse.  Debain seems to have changed pulse to be inited via systemd, there is mention in the notes to change the respawn if not using systemd.  This will no doubt be a new change for Devuan to handle.  Edit /etc/pulse/client.conf.d/00-disable-autospawn.conf:

# On linux systems, disable autospawn by default
# If you are not using systemd, comment out this line
#DXRautospawn=no

Another odd problem I had is that the XFCE desktop would randomly sometimes take minutes to appear.  This delay occurs after the LightDM login.  At the LightDM login screen I changed from Default Xsession to Xfce session and ran a few tests and the delay does not "seam" to occur (still testing).  From looking at the lightdm.log and seat0-grater.log, there are differences in the processing, and the delay can be seen in the logs on the Default Xsession runs.

I just did this a few days ago. Thanks for blazing a trail. It seems to be getting easier. Here's what I did -

Thank you so much for this!   I'm going to try this later today and see how it goes.