We can close this bug report at this point. But I do appreciate the follow up!
It turns out that there were two problems. The first was that 18.04 had misconfigured the cryptoswap so that was not working at all. I reported this separately before the release of bionic and I believe that this bug has been fixed by the maintainers. The second was that the kernel was running out of inotify watches and this prevented (for some reason) gdm3 from allowing logins to complete. The inotify watches were being consumed by the Crashplan java app. I increased the fs.inotify.max_user_watches to 1048576 and that solved the problem. I realize that this consumes some unswappable ram, but I rather have Crashplan than not.
We can close this bug report at this point. But I do appreciate the follow up!
It turns out that there were two problems. The first was that 18.04 had misconfigured the cryptoswap so that was not working at all. I reported this separately before the release of bionic and I believe that this bug has been fixed by the maintainers. The second was that the kernel was running out of inotify watches and this prevented (for some reason) gdm3 from allowing logins to complete. The inotify watches were being consumed by the Crashplan java app. I increased the fs.inotify. max_user_ watches to 1048576 and that solved the problem. I realize that this consumes some unswappable ram, but I rather have Crashplan than not.