There's no build script at the moment, but I'm considering moving the file structure around a bit. Adding a build script would be a small addition to that.
Concerning the two issues you reported:
The SerializableAttribute just sits on the custom Exception because it's good practice to make exceptions serializable to support cross-AppDomain scenarios. No part of AutoFixture explicitly relies on it, so we can just surround it with conditional compilation
UnexpectedInfo was always a hack, and something we've more or less already moved away from. AFAIR, it's only really being used in Fixture and Fixture<T>, and both of these classes are marked as Obsolete. We ought to exclude those from any Silverlight
release we might do, so I think we can get rid of UnexpectedInfo as well in that case.
It looks like AutoFixture for SilverLight would be quite possible :)