I now have Debian 12 Bookworm installed and running sort of OK in Virtualbox. Thinking about switching t it from Xubuntu 22.04 I've been testing it to see if I can install all the applications that I need. Toward that end I made a list of 70+ programs to install, and started adding them. From the list it looks like about half of them are not in the default repositories. For one of my next adventures I'll see about adding additional repositories.
I note that snap and flatpak are not installed in the default, but both can be added. I also discovered that ntp and sntp were not installed, so after 24 hours the clock displayed in the panel was way off. I've never installed a distro that didn't install them by default. I'm having a terrible time getting the guest OS to see the shared folders that I specified in the setup for the Debian 12 machine. The only thing it can see is the optical drive, but that's not an easy way to test newly installed applications with my existing files. Virtualbox is a grand PITA with shared folders, and always has been. I searched up and down the web and found lots of pages with instructions for getting shared folders working, but still no success. You open one web page of guaranteed how-tos, and you start following the list of things to do, and then you come to a line that doesn't work. When you finally decide to move on to the next page of instructions you get a completely different list of things to do, so you start out, only to eventually get to a line that won't work. And on to the next set of stuff that also eventually fails. And every time you think you've finally got it you have to shut down the guest OS and reboot it, always discovering that it still can't see the shared folders. Yesterday I rebooted Debian 12 at least 50 times, always without success. And yet, at the very beginning I swear that the shared folders appeared. I've got some blank 25GB Blu-ray disks. Maybe I should just burn a bunch of files to a disc so I'll finally be able to test newly installed applications on Debian 12. Before someone takes the trouble to point out to me that to make shared folders work you need to have VirtualBox, the Guest Additions, and the Extensions all installed, and each of the same version. Yes, I do have all of them installed, and they're all the same version. That is, they're installed in the 22.04 host, but not Debian, because they're not in the existing default Debian repositories. Wish me luck. :)
