id,summary,reporter,owner,description,type,status,priority,milestone,component,version,resolution,keywords,cc,os,architecture,failure,difficulty,testcase,blockedby,blocking,related
1936,"When lazy IO blocks, it blocks the whole runtime",guest,igloo,"{{{
module Main where

import Control.Concurrent
import System.IO
import qualified Data.ByteString.Lazy.Char8 as B

heartbeat :: IO ()
heartbeat = do threadDelay 1000000
               putStrLn "".""
               heartbeat

main :: IO ()
main = do forkIO heartbeat
          c <- B.getContents
          h <- openFile ""/dev/null"" WriteMode
          B.hPut h c
}}}

This should produce a heartbeat while it's waiting on stdin, but it doesn't, even with SMP:

{{{
dfranke@feanor:~% ghc --make brokenio.hs -threaded +RTS -N8
[1 of 1] Compiling Main             ( brokenio.hs, brokenio.o )
Linking brokenio ...
dfranke@feanor:~% sleep 5 | ./brokenio                     
dfranke@feanor:~%
}}} ",merge,closed,normal,6.8.3,None,6.8.1,fixed,lazy IO getContents blocking,df@…,Linux,Unknown/Multiple,,Unknown,,,,