Postgres failing to update?

@codinghorror in case it garners any sympathy from you, I voluntarily maintain this droplet for my local non-profit makerspace … I normally can get through this sort of thing with enough Google Fu, but I’m pretty stuck on this one and really appreciate any help. I’m going to try updating ubuntu to 18.04 using the do-release-upgrade -d I can always get back by restoring the snapshot i’m working from if necessary.