ROOTified libraries show header dependencies between final installation path and source code path

We have a project that is linking to ROOT libraries. Our cmake system generates ROOT dictionary headers. And places everything at `/project/path/to/installation/lib/` and /project/path/to/installation/include/`. `.../lib/` directory contains also `pcm` generated files during the compilation process.

Everything works fine as soon as the user loading our libraries in ROOT has rights access to the initial source directory.

If, for example, I remove the source directory we get the following error message when loading the library inside ROOT interface using `gSystem->Load("ourLibrary.so");`

Error in cling::AutoloadingVisitor::InsertIntoAutoloadingState:

   Missing FileEntry for /MY_SPOURCE_PATH/source/processes/general/inc/TRestHitsShuffleProcess.h

   requested to autoload type TRestHitsShuffleProcess

I found at some post at root-forum that defining ROOT_INCLUDE_PATH might help to solve the problem. But this did not solve the problem.

https://root-forum.cern.ch/t/cannot-find-my-rdict-pcm-files/21901/7
 
My question is why cling is trying to search for that header at our source directory? At which point this is hard-coded in the .so library?

It is not clear to me if this is a bug related to ROOT or to our cmake building system. I attach the macro we use to generate ROOT dictionary headers and compile the library.

I created the bug report after reporting my problem to the root-forum

https://root-forum.cern.ch/t/cannot-find-my-rdict-pcm-files/21901/7