Hello @Nicola_Mori,
After a brief inspection of RootMacros.cmake, it seems that that the root_generate_dictionary function uses find_file() -see here- that searches for headers in the target’s include path, regardless of the -I... options passed to rootcling.
Additionally, using include_directories() seems to be the way recommended on the documentation here.
@Axel, @pcanal, is that the intended behavior? Should we change that?
Cheers,
J.