It is somewhat abandoned.
You have made a project using attribute based caching, but the cache isn’t being hit? Does the test project included in the source work?
if you look at the test.csproj you can see the postsharp targets line:
<Import Project="..\Cache\lib\PostSharp\PostSharp.targets" />
You need that line in project containing the attributes or alternatively you can run the post-sharp installer which will handle this automatically.
If the test project isn’t working, please email me. agbell at google’s email service.