For the experiment that I mentioned, I created a new GNOME VM using all the same settings as I did for my ordinary GNOME VM, including EFI support. In the installer, I fired up GPartEd and created a boot partition and a swap partition big enough for hibernating, and the remaining 25 GiB for /.
After the installation was completed, I started the new VM and did a full update, upgrading 65 packages. Then I installed vivaldi-stable, aisleriot, and gnome-mahjongg. (Thunderbird, of course, was already present.) That caused these packages to be installed.
I didn't spend any time configuring these applications -- I just wanted to see if they would survive the change to Budgie.
Then I installed desktop.budgie, being sure to use the -c
flag, and the correct package name this time. Exactly as the Solus Help says. That got me these.
And after a reboot, when I expected to see a choice of sessions to run, all I got was a black screen. I let that run for a long time, as I watched the status indicator at the bottom of the VirtualBox window move up and down, indicating that something was being done, but eventually I killed the VM.
Note that at this point, I had not removed GNOME. I had just added Budgie, as documented on the help page.
Note that I did all of this in a Wayland session on Plasma. I'm going to switch to an X11 session now, reload the .ISO file back into the VM's CD drive, and try it from there. I'll need to log back on in order to do that, so I'll have to post this part of a message for now, and either edit it, or start a new message when I'm in the X11 session.
I'm back, this time in an X11 session, and I've replaced the GNOME .ISO in the VM's CD drive, but when I launch the VM again, the installer doesn't start. The result is exactly the same as during the Wayland session. It looks like I need to remove the VM completely, and start with a new virtual disk drive. That doesn't make sense, but I don't have a better explanation for what's happening.
So, I started over from the beginning, after removing the GNOME VM from the VirtualBox manager, I created a new virtual hard drive called Experimental, and used it to create a VM with the host name vm-experimental. I created it exactly as before, and when I was finished, I removed the .ISO file from its CD drive and launched the VM.
It was a perfectly normal GNOME VM in all respects. I started a terminal, and did a full update, after which I rebooted. And I ended up with the same empty black screen as before. That being the case, I can't use the VM to try anything differently, unless I start from the very beginning a third time, and I'm just in no mood to do that right now. I need to take a break from this case for a while, but I'll probably feel like tackling it again later, if I can think of anything that I can try differently.
In a somewhat related matter, it occurred to me when I mentioned that Thunderbird was already present in the GNOME VM, it was also already present in the Budgie VM I that I started with when I created the Xfce version. I didn't install it under Xfce, yet it remained present after I deleted desktop.gnome. I configured it with three email accounts, a couple of calendars, and an address book, and used it for three days to handle all my email.
I'm going to try launching the new GNOME VM one last time, and this time I'll leave it alone while I fix breakfast and watch some morning news. Just in case I've been too hasty until now. So, I'll close this message now and write more later, if I have anything worth saying.