I just commited an upgraded of Yesod and some associated tools to the repo. It's in a branch marked yesod_0.9, however, rather than master, as it required deleted JSONb and data-object-json, which depended on JSONb. JSONb depends on an older version of attoparsec, and was holding back other Yesod-related things that depended on the newer attoparsec. JSONb hasn't been updated since March, and on it's Hackage page[1], it says "Have you considered aeson (http://hackage.haskell.org/package/aeson), a newer, extensively benchmarked JSON parsing library?" - which gives the idea that this package might be deprecated. Feel free to merge in these updates if JSONb and data-object-json won't be missed from the repo (at least for now). [1] http://hackage.haskell.org/package/JSONb-1.0.4 -Leif Warner