Fair enough if that's what's familiar to you. I've been using Debian Linux since forever and I would be reluctant to change it for another distro. Good that the vulnerability has been been patched so hopefully you can use Sigil now.
I have my doubts about Ubuntu as it is trying too hard to be like Microsoft Windows and seems to be moving away the open source principles that Linux is based on. It may be objecting to Sigil simply because it's not in its own despository.
www.linuxinsider.com/story/sigils...
That is really strange. I downloaded my copy through the Debian Linux depository as I'm running Debian 12 Linux and I had no problems with it.
I used Sigil in Debian Linux when I was putting 'Belling the Cat' into the epub format. I'm not all that clever with this kind of thing, but I managed to figure it out. I have used Reedy's free tools as well, though I have a basic subscription to use it now. Works Ok for what I want.
So that's where it comes from. As I said I've had this image on my hard drive for the past 10 years and I found it on Faceplant before that.
I've had this image tucked away on my hard drive for the past ten years. I found it again a couple of days ago and what do you know, - nothing has changed.
The 10 of Swords, - the 21st century version.