Hugo has worked well for me building this static website overall. However, it remains generally somewhat mysterious and there have been some bumps.
After updating the hugo command it flagged several deprecated features baked into the layout template (beautifulhugo) so I found and updated that which fixed it.
The newer version of Hugo (0.85) does appear to have a new bug (6773). The basic problem is that one of the killer features of Hugo doesn’t play well with Emacs. Hugo tracks file changes to thoroughly that it sees Emacs writing a temporary file (during c-X c-S file updates) and tries to process it, but since this file is immediately renamed – which makes it disappear – Hugo stumbles and fails with an awkward error message and a file that no longer even exists. This is one of those bugs that seem insoluable where two pieces of software dig in their heels – or in this case, the big one is surely ignoring this issue – and neither will budge. To my sensibility, Hugo needs to change, but that doesn’t seem to be the prevailing view. The issue tracker does suggest workaround, and I found one that works.
With these bumps ironed out things seem to be working fine again.