I see the dilemma here, though I’m not sure that latest stable is the right terminology to use; maybe
latest release or latest official is a better choice of words. My reasoning is, the Caddy reverse proxy that drives my production environment is predicated on an xcaddy build master. This was necessary to solve the map directive issue identified in the thread Migrate to using a wildcard certificate. In that thread, I even expressed concern about moving away from Caddy 2.3.0 to the beta, but I had to make a choice. I chose the beta and it solved the issue and had no other visible impact on the production environment. IMO, that’s the latest stable version of Caddy even if it’s not deemed the latest official version.
I wonder if a way around this may be to allow both behaviours? For example, caddy upgrade for the existing behaviour and caddy upgrade -master to allow the latest tweaks from the master to filter through.
I wonder if there’s any harm in leaving the backup there (instead of naming it caddy.tmp, it could be named caddy.backup), but overwriting it when Caddy is next upgraded? This provides an easy path to revert back to the last release prior to the upgrade if required. It would have been useful in this instance i.e. to revert back to the 2.4.0-beta.1 from 2.3.0.