While trying to solve an html export error, I found out that VorbisLibPath for HTML has a naming problem.
On OSX the files that are looked for linking are located under …/lib/HTML5/(libvorbisxxx.bc) when the launcher build (4.9) is installed.
However, in the source the folder is called as Lib, and is compiled as is.
This will create a file not found error in python while emscripten is crunching numbers, for case sensitive journaled file systems.
Also can be a problem for Android builds.
Here is a link to the class:
/Engine/Source/ThirdParty/Vorbis/VorbisFile.Build.cs#L34
/Engine/Source/ThirdParty/Vorbis/Vorbis.Build.cs#L49