Hi, Upgrading to Data.Binary was fun, and is clearly the right direction for the future, but its broken at the moment. The authors hope that with a bit of luck and a google summer of code project they might have the required build changes done so that we can use it reliably on various GHC versions, but that's of no comfort to us for the moment. As a result, I've backed out the patches moving us to Data.Binary, and have flipped back to our bad version of Binary - which turns out to produce 30% smaller files and have similar performance... Apologies to all, but that means all your Yhc.Core files will be broken once more - please clean and rebuild. Several of the buildbots are still down, but I know the reason in each case and will be working to get them all back to life shortly. Thanks Neil