–usn-policy: Fatal error => Value cannot be null. Parameter name: source looks like the same problem, and if so it looks like the bug got fixed in v2.0.4.18-2.0.4.18_canary_2019-05-12 but is not in a beta yet.
Improved filter handling for empty filters, thanks @dgehri
Fix for –usn-policy: Fatal error => Value cannot be null. Parameter name: source #3762
There’s no workaround given, but I’d think you could read Filters and give something that does nothing.
A regular expression exclude that requires an empty string file path might do that, i.e. --exclude="[]"