I'm running into a problem handling requests with streaming request bodies that fail - using http-client, the failure takes a long time (potentially never) to propagate. Simple code (runnable project here):

{-# LANGUAGE OverloadedStrings #-}

import Control.Monad
import Data.Conduit.Combinators
import Network.HTTP.Conduit
import System.Environment

a :: IO ()
a = do
  manager <- newManager tlsManagerSettings
  request <- parseUrl "http://httpbin.org/status/409"
  void $ httpLbs request manager

b :: IO ()
b = do
  manager <- newManager tlsManagerSettings
  request <- parseUrl "http://httpbin.org/status/409"
  void $ flip httpLbs manager request
    { requestBody = requestBodySourceChunked $ repeatM $ return "a"
    }

Running "a" above works as expected (propagating the error immediately). Running "b" has variable results, mostly never propagating the error. Looking at the wire, I can see that the 409 status comes back, but the exception does not propagate.

Is there something I can do here to get quicker failure? Thanks!

Mark