Install DWT2 using DMD and Tango

[Fabian]

Hi
I'm trying to install DWT2 to create GUI applications with D.
I have downloaded DWT2 with TortoiseHg already and I've installed Ruby 
and Rake. But when I try to build the packages I get the following error 
message:

http://imageshack.us/photo/my-images/62/dwt2error.png/

Is there anybody who can help me?
I believe it's possible to use DWT2 and Tango - isn't it?

Greetings Fabian