Hi .
Nope, all my headers are in correct location, in source directory.
Where I’ve used term intermediate above, I meant in sense of indirectly including a header file through a chain of #includes (see code added to question). So if A includes B and B includes C, then A is including C indirectly via an ‘intermediate’ file (B).
Sorry for confusion, I guess it wasn’t a very good choice of word to use.