aggregate gpr project paths

[sbelmont700@gmail.com]

Hi,

Does anyone know (or at least surmise) what the rules are regarding the Project_Path attribute when one aggregate gpr project file builds another?

Rules as written, it says:

"Each aggregate project has its own Project_Path (thus if agg1.gpr includes agg2.gpr, they can potentially both have a different Project_Path)...the project path for agg2.gpr is not influenced by the attribute agg1’Project_Path, nor is agg1 influenced by agg2’Project_Path."

Ok, so agg1 and agg2 each get their own Project_Path, both completly separate, not influenced by each other, and never the two shall meet.  Fine.

So I try it, using something like this:

aggregate project a is
  for project_path use ("dir1");
  for project_files use ("b.gpr");
end a;

aggregate project b is
  for project_path use ("dir2");
  for project_files use ("default.gpr");
end b;

And expect that, given the documentation, default.gpr should only be able to with in gpr files from dir2.  But this is not the case; default.gpr can ONLY see dir1, and not dir2.  Cranking up the verbosity (-vP2) gives the error message "'for Project_Path' has no effect except in root aggregate" when parsing b.gpr, which implies an exact opposite behavior from that described: b actually inherits the Project_Path from a, can NOT have a different one, and is directly influenced by it.  Indeed, if I change a to have both dir1 and dir2 (with nothing specified in b), default can see both directories.

Does anyone know what the expected behavior actually is, or ought to be?  I can't even untangle it to the point where I could call it a bug or not.  If it is the case where b inherits the path from a, is there any standard way to reference it or append to it?

GPRBUILD Community 2019 (20190517) (x86_64-pc-linux-gnu)

-sb