Dropbox data folder cannot be mounted on macOS

[otherguy]

Initially reported in #2, Dropbox (client version 87.4.138 and later, currently up to 95.4.441 as of April 2020) refuses to sync when a local folder is mounted to the Dropbox data volume (/opt/dropbox/Dropbox) on macOS.

The error found in the Dropbox logs is:

File "nucleus_python.pyx", line 87, in nucleus_python.NucleusSyncEngine.cinit
nucleus_python.SyncEngineError: Initializing engine 
|>> Initializing platform 
|>> Checking if filesystem is supported
|>> Filesystem is not supported: "FUSE"

The dropbox-filesystem-fix patch is now unable to work around this issue.

[jonmchan]

I know this is not a great long term solution... but just as a workaround... we could consider using docker-sync... http://docker-sync.io/

Docker-sync allows you to use the native mount and then unison syncs it to the host... I know it'll be syncing on top of syncing, but better than nothing right?

Also, not sure if the new mutagen sync holds any promise - I haven't tested it myself, not sure what kind of filesystem it mounts or shows to the container. https://docs.docker.com/docker-for-mac/mutagen/