Make sure that agmake behaves the same as POSIX make in case of tricks concerning .PHONY targets
This trick is described here: http://stackoverflow.com/questions/2145590/what-is-the-purpose-of-phony-in-a-makefile/28451622#28451622
Generally, the matter is that phony targets must be always rebuilt without staleness check, and executing a phony target makes the dependent targets stale.