Yesterday my encrypted home dir ran out of space and ecryptfs got into a problem where it could not write changes (including deletions I was making to reclaim space), and it became unmountable. All my data was safe on another mounted volume, so today I rebuilt the machine with a fresh install of Ubuntu and reconfigured everything. All seems to be working well again; there will be a few things I haven't remembered to install, but much more that I had installed and would never have needed again. I've reconfigured docker to store stuff on the spinning disk (it was a docker container that cause the problem), and made some other similar tweaks to keep the home dir size under control. Managed to do other work as all this was going on, too, using the laptop and the desktop.