"InternalIOException getAddrInfo: does not exist (error 10093)" on Windows 8

Question

Why is such simple code not working?

import Network.HTTP.Conduit
import qualified Data.ByteString.Lazy as L

main :: IO ()
main = simpleHttp "http://www.dir.bg/" >>= L.putStr

It results in the following error:

TestConduit.exe: InternalIOException getAddrInfo: does not exist (error 10093)

Ogdan

Answer 1

You have to use withSocketsDo to initialize sockets. Like this:

import Network.HTTP.Conduit
import qualified Data.ByteString.Lazy as L
import Network (withSocketsDo)

main :: IO ()
main = withSocketsDo
      $ simpleHttp "http://www.dir.bg/" >>= L.putStr

Ogdan

Actually, you should always use withSocketsDo, if on Windows or not. Then you'll never have this problem. :-) – Jeneejenei

I'm curious why this initialization is not happening behind the curtains or on-demand automatically? – Ogdan

@Ogdan or designed so that well-typed code doesn't blow up, right? There's really no excuse for this kind of thing in haskell. – Hornblende

Yes, but we could put a lot of other stuff. We could brake withSocketsDo on parts and make people initialize it every time. I think this is non-sense. If there are a ways to make people write more correct code implicitly it will be better. – Ogdan