Re: synchronizing gnus sessions on multiple computers

["Roland Winkler" <winkler@gnu.org>]

On Fri, Sep 10 2021, Eric Abrahamsen wrote:
> "Roland Winkler" <winkler@gnu.org> writes:
>> -- I realized that testing all this does not require two different
>> machines.  But two instances of emacs running on one computer
>> effectively give the same situation to play with.  It seems that a
>> running gnus session does not warn the user that another emacs instance
>> has fiddled with files such as .newsrc.eld.  Is this true?
>
> Yes, the .newsrc.eld file only gets written when you save Gnus ("s" in
> the *Group* buffer), and I would absolutely not try to update files for
> a Gnus that's still running, it will not handle that gracefully. It
> should, however, be enough to shut Gnus down first (you can see the
> `gnus-clear-system' function to see what happens then), rsync, then
> restart Gnus.

...It seems that the command gnus-group-exit (bound to q in the group
buffer) is really doing the complete job.  This command also calls
gnus-clear-system, besides other things.

The gnus info pages note repeatedly

  Gnus gives you all the opportunity you could possibly want for
  shooting yourself in the foot.

So I'll have to set up things such that a careless rsync cannot do too
much damage.  I guess when switching from machine A to machine B it is
always machine A (i.e., the source for rsync) where I should run
gnus-group-exit which will also flush everything to disk that needs to
be rsync'ed to machine B.  When rsync has done its job (A -> B), I can
start working on B.  Then, when I am done working on B, I can run
gnus-group-exit on B, rsync B -> A, and continue working on A...

Sounds like a plan.