Using DarkTable 4.6.1 with images/sidecars shared between two systems on an external drive

gistfile1.txt

I wanted to be able to put my raw images on an external drive and edit them with DarkTable from both a Linux and a MacOS system.
The following approach seems to work?

- Install DarkTable on both Linux and MacOS. In both copies, point the base directory naming pattern to a folder on my external drive (prefs->import->base directory naming pattern). 
I also went to prefs->storage->look for updated xmp files on startup and checked it.
- On the Linux box, do a *copy import of my raw files to get them on the external drive, construct the xml sidecar files, and
build the library.db file for the local OS.
- On the MacOS box, do a *NON copy import* of my external drive to grab the sidecar files and build the library.db for the
local OS.

After this initial setup, test out the workflow:
- Modify an image one one system (e.g., add a watermark to a test image).
- Move the external drive to the other system and do a *NON copy import*  to rebuild the library.db with the updated xmp files.
Verify you can see the updated test image in the library.

And that's it.

A couple of notes: (1) think through what file system you want on the external drive, since both systems have to be able
to read/write it. I have Paragon Software's NTFS driver on my Intel silicon MacOS box, so I formatted the drive as NTFS and that
works fine. YMMV. (2) I couldn't get passing a PICTURES_FOLDER variable via the conf parameter to work; I had to edit the
prefs directly to get it to take.

Thanks to the folks on https://webchat.oftc.net/?channels=%23darktable for getting me pointed in the right direction!