my first link error: Error 42: Symbol Undefined __moduleUnitTests

[Fei]

I'm trying to compile my first d sample, winsamp.d, using dmd 2.025 for windows.

dmd winsamp.d gdi32.lib

everything seem ok but I got a link error :
Error 42: Symbol Undefined __moduleUnitTests

what lib should I include for moduleUnitTetst?