How do I get a bit more logging?

I’m running Duplicati on a Mac from launchd as follows:

/Applications/ --webservice-port=8200 --log-file=/Library/Logs/duplicati_server.log --verbose=true

but the file duplicati-server.log remains empty. The LaunchDaemon has set stdout to /Library/Logs/duplicati_out.log and stderr to /Library/Logs/duplicati_err.log. duplicatie_err.log is not created (a good thing, I guess) and duplicati_out.log only contains “Server has started and is listening on, port 8200”, so it works. duplicati_server.log remains empty.

How can I get a bit more information about what is going on?

If you add --log-level=profiling that should be the most logging available.

Does the capitalisation matter (“profiling” versus “Profiling”)?

As far as I know, command line options are not case-sensitive.