I was having trouble serving files from a location using shareFilesFromDirectory and tracked it down to a couple of lines in Socket+File.swift. This may be completely the wrong solution and it seems odd that no-one's picked up on it but it's working for me now so if it helps anyone ...

line 10:
#if os(iOS) || os(tvOS) || os (Linux) || os (macOS) // ka added macOS

and line 44:
#if os(iOS) || os(tvOS) || os (Linux) || os (macOS) // KA: Added macOS