On Tue, 17 Feb 2026 16:08:08 +1100 Timothy Allen <[email protected]>
wrote:
> Apparently what's happening is that after the system boots, the
greeter runs
> under the `gdm3` user, which is apparently counted as a user session,
so per-
> user units like syncthing are started and bind the relevant ports. When I
> login, that starts a *new* user session, and *another* copy of
syncthing, which
> fails to start because the ports are already bound. Eventually (I'm
not sure
> how) gdm3's copy of syncthing gives up, or is stopped, so days later
when I
> notice the problem I can start syncthing and it works perfectly.
I had tried to stop gdm3 from starting syncthing by trying to mask the
service, but gdm3 is a dynamically created user with a home directory on
a tmpfs, so the next time I rebooted the problem returned.
I've since discovered a symlink to syncthing.service in
/etc/systemd/user/default.target.wants/ which I guess makes it start for
*all* users by default. I've removed that symlink and that *seems* to
have addressed the issue. I don't recall adding that symlink myself, if
it was added by installing (or upgrading) the package it would be nice
if it did *not* do that.
Timothy.
