I haven’t updated my RO images to Stretch yet, but timekeeping and handling the RO status have nothing to do with emoncms, that’s the OS. Even “ntp” will not work on RO OS’s without installing the “ntp-backup” mod. Any changes made to overcome the RO changes should be part of those RO changes, otherwise those changes are incomplete.
Just adding “ntp” to the dependencies will not make the fake-hwclock file writable, nor will it include Glyns more recent hack to reset the time after boot as that too is a separate bespoke mod, AFAICT adding ntp to the dependencies here in the emoncms install guide has no purpose, unless emoncms is dependent on it regardless of whether it’s an RO OS or not.
Questioning the necessity of the packages is a good thing, we should only be installing what is necessary to this part of the install, as a rule rather than justifying why it should be removed, we should be removing everything we cannot justify keeping in.
Perhaps we should even include a little table or list of dependencies and why they are needed and what they do as part of the guide, that would help with questions like these and a couple of years down the line we will all know why we included certain packages. Take the dio PECL package as an example, if it was documented that we were installing that to support accessing the serial port direct from emoncms, it may have been dropped in any one of the many documentation revisions there has been over the years.
From another recent discussion about installling emoncms
I get the impression he was rather stressed by the issue he was battling when he wrote that comment, but tone aside, its a fairly valid point.