Makefile experts, unite!

[Andrei Alexandrescu via Digitalmars-d]

Phobos' posix.mak offers the ability to only run unittests for one module:
make std/range/primitives.test BUILD=debug -j8

... or package:

make std/range.test BUILD=debug -j8

It runs module tests in parallel and everything. This is definitely 
awesome. But say I misspell things by using a dot instead of the slash:

make std.range.test BUILD=debug -j8

Instead of an error, I get a no-op result that looks like success. How 
can that situation be converted to an error?


Thanks,

Andrei