To begin with, I haven't gotten very far.
I'm reading through the manual, and the first thing I figured out what to do is write the package definition,
http://pastebin.com/2q7LCv2i .
I'm not sure what exactly to do with it, it was something about putting it in the guix build tree. Though I'm not 100% sure what that is.
Another thing that I'm a bit confused about is the base32 string in the beginning of each store file in /gnu/store*, is it after you build a package def, you "guix hash" it or is there another process.
And with the service definition for dmd, I think we can worry about that later, after we've ported guix.