Here is the issue:
When the syncthing app runs it launches the menu tray app:
/Applications/Syncthing.app/Contents/MacOS/Syncthing
The menu tray app in turn launches the syncthing program but uses the path to the mounted dmg:
/Volumes/Syncthing/Syncthing.app/Contents/Resources/syncthing/syncthing
This is visible by running a ps while the dmg is mounted and syncthing is running:
ps -fe | grep -i syncthing
501 2568 1 0 1:17PM ?? 0:00.45 /Applications/Syncthing.app/Contents/MacOS/Syncthing -psn_0_1212712
501 2569 2568 0 1:17PM ?? 0:00.06 /Volumes/Syncthing/Syncthing.app/Contents/Resources/syncthing/syncthing -no-browser -no-restart -logfile=default
501 2570 2569 0 1:17PM ?? 0:04.44 /Volumes/Syncthing/Syncthing.app/Contents/Resources/syncthing/syncthing -no-browser -no-restart -logfile=default
501 2592 2538 0 1:17PM ttys000 0:00.00 grep -i syncthing
Where
/Volumes/Syncthing/
is the location where syncthing.dmg is mounted.
I have two (ugly) ways to work around this issue, pick one:
1)
Follow the instructions on the syncthing web site
https://docs.syncthing.net/users/autostart.html#macos
to automatically start syncthing by using
/Applications/Syncthing.app/Contents/Resources/syncthing/syncthing
as the program to launch at login. This works without the dmg being mounted but does not launch the menu tray program.
2)
Create a symbolic link from the mount point to the actual location.
Eject the dmg image.
Create a symbolic link where the dmg was previously mounted:
sudo mkdir /Volumes/Syncthing
sudo ln -s /Applications/Syncthing.app/ /Volumes/Syncthing/Syncthing.app
This allows the syncthing menu tray to run and launch the real syncthing program from the wrong path via the symbolic link.
This is a really ugly hack to work around the bug. Iâm OK with the ugliness since I doubt this will be fixed for my old version of macOS.