I just downloaded the latest Byzantium image from the PureOS official download site to install in Gnome Boxes. Picking the ISO and trying out PureOS is fine, but after running the installer I get a number of problems. Firstly, I can’t proceed without encrypting the partition. Secondly, after finalizing the install I prompted to restart, remove the removable media and press ‘Enter’. After that I get an endless list of disk errors which seems to never end. Terminating this process, and restarting the Box gets me back to try out PureOS.
I think I’ve run into this before, but it’s been a while. I think when you are prompted to remove the installation media, you have to click the three dots menu, then choose Preferences->Devices & Shares, and then I think there will be an entry under CDROM/DVD Drive, and you do have to remove that. I also think you have to click remove twice for it to actually work or something like that. Or maybe you have to click remove, close the preferences window, and then open the preferences again to make sure it’s actually removed.