DMD2028+Phobos cannot compile sample

[Sam Hu]

When compile winsamp.d in dmd\sample\d: 

C:\DTwo\samples\d>dmd winsamp gdi32.lib winsamp.def
OPTLINK (R) for Win32  Release 8.00.1
Copyright (C) Digital Mars 1989-2004  All rights reserved.
winsamp.obj(winsamp)
 Error 42: Symbol Undefined __moduleUnitTests
--- errorlevel 1

C:\DTwo\samples\d>

And several other samples can not pass compiler:chello.d d2html.d 
Just wanna know whether this is the case or just my own installation problem?Thanks so much!!

Sam