Should be able to build the lib with just telling it it's a lib, and setting the inc. path.
[ ] Actually... It could even just add every dir with headers to the inc. path
[ ] Obviously, it would cause trouble for some source layouts e.g. with multiple identically named local headers (incl. name clashes across aux stuff (not ext. but) embedded into the src tree), so it could be disabled by default
Should be able to build the lib with just telling it it's a lib, and setting the inc. path.