The RTS chokes on SIGPIPE (happens with runInteractiveCommand)

Consider the following code.

-- code based on example by steven_ashley on #haskell
import System.Process
import System.IO
import Control.Exception

main = do
    data <- readFile "core"
    (inp,out,err,pid) <- runInteractiveCommand "cat"
    print "before"
    finally (hPutStr inp data)
            (print "after")

This program, when run with a large enough core file in the current directory, will print "before" and then exit.

What happens (according to strace) is that the RTS closes the input end of the output pipe of the cat process (the one associated with the out variable). Then, cat tries to write some of its output and gets killed by SIGPIPE. This in turn closes the input end of its input pipe. When the Haskell program writes its next chunk of data, it is killed by SIGPIPE itself.

I believe the right fix for this is for the RTS to ignore SIGPIPE. The write syscall would then return EPIPE in the above scenario, which can be handled by the normal exception mechanism.

Trac metadata

Trac field	Value
Version	6.7
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Runtime System
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture