The problem manifests itself when the naive parser ignores
any conditions that might have been set in the makefiles
included with subsequent attempt to run a target which has
its actual rule defined within e.g. "ifdef DEBUG" clause
(as is the case for conf.d/test.mk); that will fail with
no proper diagnostics currently.

Maybe this would be of some use (but then again maybe not):
http://stackoverflow.com/questions/3063507/list-goals-targets-in-gnu-make