Adding include paths


I would like to know how I can add a path to be searched when a #include directive is interpreted by root in interactive session.
I was able to add a path for loading macros using .L/.x commands (adding a path in Unix.*.Root.MacroPath line of .rootrc), but it seems that path is ignored when #including (no difference using angular brackets <> or double quotes “”). For example, if a

works, a

can still fail (assumed that Test.C is in a custom directory included in Unix.*.Root.MacroPath).

Thank you!

Currently: ROOT 5.10.00e/CINT 5.16.8 compiled on i686

use gSysatem->AddIncludePath(path);

see also Users Guide.