> I guess you aren't keen on Java then?

Can you explain more? I don't follow.

Java dependencies are too complicated for make. See https://www.oreilly.com/library/view/managing-projects-with/...

I'm not keen on Java for other reasons. The fact that a single .java file can generate multiple .class files is annoying but not something tools can't handle (it's actually similar to .h files for C/C++ - remember, we only need the complete dependency graph for the rebuild, not the current build).

The main part that's difficult for humans is if there's a non-public class at top level rather than nested (I forget all the Java-specific terminology for the various kinds of class nesting).