Make bootable? Or did you mean "make executable"?

Are you trying to boot a 64-bit OS on a 32-bit system?

This is fixed in chimaera/ceres: https://git.devuan.org/devuan/lightdm/s … /changelog

The fix is also in beowulf-proposed-updates and will be in the 3.1 point-release.

Distrowatch ratings are based on the number of page views for each distro's summary page. That may not be a good indication of how many people actually use it. (Note: I know one person who does use MX.)

It's not clear whether you want to archive just your installation or if you want the whole dvd set (i.e. the whole repo).

If you choose a mirror during the install, it doesn't matter whether you use the dvd or the netinstall iso - it will pull from the repo and will be current.

If you really want ALL the packages from the repo on dvd, then take the devuan dvd for installing a fresh system and take the debian dvd set to pull any individual packages you might want that aren't on the devuan dvd. Just don't install any packages from the debian disks that need systemd.

If you really want it to still work in 20 years, you should probably install to a virtual disk, so you aren't limited by lack of hardware support in 20 years.

Last time I upgraded my beowulf was exactly one week ago, and I see nine packages for upgrade today. You might not have all these packages installed. If you're not seeing the new kernel, maybe you don't have the kernel metapackage installed - linux-image-amd64 (or similar)

aptitude -s full-upgrade
The following NEW packages will be installed:
  linux-headers-4.19.0-11-amd64{a} linux-headers-4.19.0-11-common{a} linux-image-4.19.0-11-amd64{a} 
The following packages will be upgraded:
  librsvg2-2 librsvg2-common libvncclient1 libvncserver1 libx11-6 libx11-data libx11-xcb1 linux-headers-amd64 
  linux-image-amd64 
9 packages upgraded, 3 newly installed, 0 to remove and 0 not upgraded.

The installer includes Recommends by default. If you wanted to alter that, you could switch to another virtual console with alt-F2 during the install and make a 00norecommends file in /etc/apt/apt.conf.d/ that contains 

APT::Install-Recommends "no";

Do that after the package manager is configured but before tasksel starts installing packages.
alt-F1 to get back to the installer.

Yeah, you can operate without the microcode, but that's still really weird. I just tested with and without amd64-microcode and intel-microcode, and it works in all cases. The script removes crypttab and resume from the initrd. My system is encrypted.

Meanwhile, someone else is having the same problem on a debian 10 system without the microcode. In that case, 'file -L /initrd.img' gave output with 'gzip compressed' twice, which broke the test.

If you want the microcode to be present in an installation made from your snapshot without having to add it after the installation, there's a way to do that.

save_work="yes"
Make a snapshot without the microcode.
chroot /home/work/myfs and install the microcode.
Make another snapshot using the no-copy option (re-squash and run xorriso)

Then the initrd used to boot the iso won't have the microcode, but any installs made from that iso will have it.

Looks like xz-utils got removed. I hope that's all it is.

I cloned your repo, installed the build-deps and built packages in beowulf with no problems using dpkg-buildpackage -us -uc -b

I'm trying to install ceres in a chroot right now, and it's going to take an hour to install git. I don't know wtf the problem is. It normally would take about one minute. I'll get back to you on that.

Edit: The same works for me in chimaera.

I got an ubuntu iso (20.04.1-desktop)
Booted it in qemu and used unmkinitramfs to unpack it into an empty directory.
Re-packed it as gzip with find . -print0 | cpio -0 -H newc -o | gzip -c > ../initrd.img-custom
I then unpacked the custom initrd to verify that the amd64 microcode was still there. It was.

Note 1: I chose gzip because the command was easier to type than xz, and I did not attempt to figure out the correct lz4 command. I just wanted to make sure the microcode didn't get lost.

Note 2: Since it was a live session, there were only dead symlinks in /boot, so I used /cdrom/casper/initrd for the extraction.

Edit: Yup. ^^^

So, you can either change the compression to a supported type as I mentioned above, or you can manually unpack the initrd, remove crypttab, repack it and replace /home/work/iso/live/initrd.img with the modified copy, then re-run refractasnapshot and just select the option to re-run xorriso. You must have set save_work=yes in the config file for this to work.

If you keep the lz4 and do the manual re-pack, your users may run into the same problem if they try to make a snapshot on an encrypted system.

The kernel does not get upgraded automatically unless you have the kernel metapackage installed - linux-image-amd64 (or other arch).  Either install that or install the specific kernel package you want.

I have linux-image-5.6.0-2-amd64 in chimaera, and I think that's the latest.

You already have the only line for chimaera in your sources.list. There won't be any -updates or -security repos until after chimaera goes stable (or maybe after bullseye goes stable).