Modifying JW_PKG_XXX_PATH in pre-local.mk is fragile.
Amending PREREQ_RUN in pre-local.mk works, but only with $(JW_PKG_NO_CACHE) == true, or if "undefine JW_PKG_XXX_PATH" is also added in pre-local.mk. Otherwise JW_PKG_XXX_PATH will not be recomputed, because it's already defined from the cache.
Introduce the new variable PREREQ_RUN_ADD to solve that. If it's defined, it automatically invalidates the JW_PKG_XXX_PATH variables and sets them up for recalculation in py-path.mk / ldlibpath.mk.
Signed-off-by: Jan Lindemann <jan@janware.com>
Jan Lindemann
2cafd60b71