avoiding depending on latest version of process except on Windows

Annex/Multicast.hs

@@ -5,6 +5,8 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
+{-# LANGUAGE CPP #-}
+
 module Annex.Multicast where
 
 import Config.Files
@@ -14,6 +16,9 @@ import Utility.PartialPrelude
 import System.Process
 import System.IO
 import GHC.IO.Handle.FD
+#if ! MIN_VERSION_process(1,4,2)
+import System.Posix.IO (handleToFd)
+#endif
 
 multicastReceiveEnv :: String
 multicastReceiveEnv = "GIT_ANNEX_MULTICAST_RECEIVE"
@@ -21,8 +26,14 @@ multicastReceiveEnv = "GIT_ANNEX_MULTICAST_RECEIVE"
 multicastCallbackEnv :: IO (FilePath, [(String, String)], Handle)
 multicastCallbackEnv = do
 	gitannex <- readProgramFile
+#if MIN_VERSION_process(1,4,2)
+	-- This will even work on Windows
 	(rfd, wfd) <- createPipeFd
 	rh <- fdToHandle rfd
+#else
+	(rh, wh) <- createPipe
+	wfd <- handleToFd wh
+#endif
 	environ <- addEntry multicastReceiveEnv (show wfd) <$> getEnvironment
 	return (gitannex, environ, rh)
 

git-annex.cabal

@@ -319,7 +319,7 @@ Executable git-annex
    stm (>= 2.3),
    mtl (>= 2),
    uuid (>= 1.2.6),
-   process (>= 1.4.2.0),
+   process,
    data-default,
    case-insensitive,
    random,
@@ -384,7 +384,7 @@ Executable git-annex
 
   if (os(windows))
     Build-Depends: Win32, Win32-extras, unix-compat (>= 0.4.1.3), setenv,
-      process (>= 1.3.0.0)
+      process (>= 1.4.2.0)
   else
     Build-Depends: unix
     if impl(ghc <= 7.6.3)