I'm trying to write a tool that will send and receive messages over ssh by running `ssh foo@bar 'my-tool --server'`, getting the `stdin` and `stdout` handles, and then communicating via these handles. 

Before I do that, I'm trying to write a simpler tool that will send a message to `echo` and receive it back. 

```
main = do
  (Just hin, Just hout, _, _) <-
    createProcess (proc "/usr/bin/echo" []) {std_in = CreatePipe, std_out = CreatePipe}
  hSetBuffering hin LineBuffering
  hSetBuffering hout LineBuffering
  forkIO $ getMessages hin
  sendMessages hout
```
This fails with
```
sesh: fd:4: hGetLine: illegal operation (handle is not open for reading)
sesh: fd:5: hPutStr: illegal operation (handle is not open for writing)
```