How to run unittests?

[al]

It seems that unittests are not run (I've tried putting while(1){} and writef() there - no effect).

Even this code doesn't run assert():

import std.stdio;

int main(string[] args)
{
	assert(args.length == -1);
	writef("shouldn't work!");
	return 0;
}


I'm using:

dmd -debug -w -unittest -run main.d

Is there a secred debug switch, or is it simply a bug? Which version of DMD is usable? (I've got v1.050)