The short version of my problem is: when I start two instances of darktable, the second one just overwrites the library.db.lock file. It appears darktable is ignoring the database lock.
Medium version of what I'm trying to do:
I have darktable on my laptop, along with all of my files.
I also have darktable on a desktop with a GPU.
I can mount my laptop harddrive on the desktop so the desktop can browse and edit files on the laptop over the network.
I want to have darktable on the two machines operate on the files on the laptop and be aware of changes made by the other machine. For instance, when I open darktable on the desktop, I want to automatically see any edits that were made on the laptop.
This works perfectly by using the --cachedir, --configdir, and --library options and pointing them all to the shared folder.
The problem is if I accidentally open darktable on both machines simultaneously, it appears they're both editing the database, and at best this causes confusion. At worst, I'm concerned about database corruption.
How can I diagnose why the lock is being ignored?
Thanks in advance!