Hi all, So I decided to upgrade one of my programs to Warp 2.x, but I'm getting stuck on generating the Response from a "sourceFileRange" (from Data.Conduit.Binary). Here's a snippet of the relevant code: serveFile :: Integer -> [(Maybe Integer, Maybe Integer)] -> IO Response serveFile fsz [(l,h)] = do let l' = maybe 0 id l let h' = maybe (fsz-1) id h let n = (h' - l' + 1) let src = mapOutput (Chunk . fromByteString) $ sourceFileRange sfp (Just l') (Just n) return $ responseSource partialContent206 [ hdrContentLength n , (hContentType, mimeType) , hdrContentRange l' h' fsz , hdrAcceptRangesBytes , hdrConnectionClose ] src When I try this I get: src/Handlers.hs:96:54: No instance for (MonadResource IO) arising from a use of `sourceFileRange' Possible fix: add an instance declaration for (MonadResource IO) In the second argument of `($)', namely `sourceFileRange sfp (Just l') (Just n)' In the expression: mapOutput (Chunk . fromByteString) $ sourceFileRange sfp (Just l') (Just n) In an equation for `src': src = mapOutput (Chunk . fromByteString) $ sourceFileRange sfp (Just l') (Just n) ... which I guess kinda makes sense -- you'd need a ResourceT (or similar) in the monad stack. I'm just not sure how or where to introduce the ResourceT to get this working. If I introduce an explicit type signature for "src", src :: forall m . MonadResource m => Source m (Flush Builder) then that line compiles, but I get the equivalent error at the usage site of "src" in the third argument to "responseSource" (which again also makes sense). Anyone got any pointers? Regards,