[OT] Git plus Syncthing: breaking hard links

[Eric Abrahamsen <eric@ericabrahamsen.net>]

This isn't really a Org question at all, but you all are smart and
friendly people, and are likely to have run into this situation before.
So I'm trying here before I turn to StackOverflow!

I have Org files in a git repo, synced across two Linux machines. At the
same time, I have a few directories on these computers that I sync with
colleagues, via Syncthing.

One of these colleagues also uses Org, so instead of giving her access
to my Org git repo, which would be a bit too much exposure, I hardlink
some of the Org files into the Syncthing directories, and she accesses
them there. With auto-revert-mode turned on, it's not too bad.

Except that the hardlinks keep breaking! There are so many different
systems interacting here that I have no idea where to even start
looking. She's on a Mac, not Linux, and uses a fairly recent version of
Emacs, plus Org from the ELPA package. She is *not* using git on her
machine, just Syncthing and Emacs.

I'm inclined to blame Syncthing, but I really don't know where to start
debugging. If any of you have any relevant experience, or any advice
about where to look, that would be much appreciated. Otherwise, please
excuse the off-topic post...

Thanks,
Eric