Unable to cloud compile with symlinked files

With a directory structure like this

src
 - main.ino
 - sub
   - lib1.h
 - sub2  symlinked
   - lib2.h 

where sub2 is a directory symlink to a directory outside of the project directory. I can include sub/lib1.h fine, but /sub2/lib2.h does not include. The cloud compiler gives

fatal error: sub2/lib2.h: No such file or directory

and sub2/lib2.h does not appear in the list of included files. Presumably the symlinked directory is not being uploaded properly? This compiles fine with the local compiler. If I use the lib directory I get the same problem.

Perhaps I am approaching this wrong and symlinks are not the best idea - when having multiple projects that all need to share some common code, what’s the best way to include one common file in all the projects?