Can't run unit tests on Win7 64-bit?

[pineapple via Digitalmars-d-learn]

I have a super simple D file that looks like this:

unittest{
     import std.stdio;
     writeln("hello");
}

On OSX Mavericks I run "rdmd --main -unittest test.d" and I get a 
nice "hello" and everything is well.

On Win7 64-bit I run "> rdmd --main -unittest test.d" and rdmd 
seems to hang. It never outputs "hello", and it doesn't terminate.

Is this a mistake on my part? Or just an annoying bug?