I've run into a situation where I want to control the include dirs in a recursive make. I am adding include paths to recursive invocations via --include-dir=, when I find one which matches my criteria.
However, GNU Make seems to be holding on to these directories from high level invocations to lower ones. The construction of include paths, via --include-dir, should be per-invocation,
and not shared with children, except by providing --include-dir=... on the recursive command line.
The attached small makefile illustrates and documents the problem.
Is there a way to suppress this behavior?