convert processTranscript to use hGetLineUntilExitOrEOF

It does use it on both stdout and stderr. It seems unlikely the problem
could really affect stdout, but the unix implementation of it combines
both into a single handle in any case.

Utility/Process/Transcript.hs

@@ -15,7 +15,6 @@ module Utility.Process.Transcript (
 ) where
 
 import Utility.Process
-import Utility.Misc
 
 import System.IO
 import System.Exit
@@ -63,10 +62,10 @@ processTranscript'' cp input = do
 			, std_err = UseHandle writeh
 			}
 		withCreateProcess cp' $ \hin hout herr pid -> do
-			get <- asyncreader readh
+			get <- asyncreader pid readh
 			writeinput input (hin, hout, herr, pid)
-			transcript <- wait get
 			code <- waitForProcess pid
+			transcript <- wait get
 			return (transcript, code)
 #else
 {- This implementation for Windows puts stderr after stdout. -}
@@ -77,16 +76,18 @@ processTranscript'' cp input = do
 		}
 	withCreateProcess cp' $ \hin hout herr pid -> do
 		let p = (hin, hout, herr, pid)
-		getout <- asyncreader (stdoutHandle p)
+		getout <- asyncreader pid (stdoutHandle p)
-		geterr <- asyncreader (stderrHandle p)
+		geterr <- asyncreader pid (stderrHandle p)
 		writeinput input p
-		transcript <- (++) <$> wait getout <*> wait geterr
 		code <- waitForProcess pid
+		transcript <- (++) <$> wait getout <*> wait geterr
 		return (transcript, code)
 #endif
   where
-	asyncreader = async . hGetContentsStrict
+	asyncreader pid h = async $ reader pid h []
-
+	reader pid h c = hGetLineUntilExitOrEOF pid h >>= \case
+		Nothing -> return (concat (reverse c))
+		Just l -> reader pid h (l:c)
 	writeinput (Just s) p = do
 		let inh = stdinHandle p
 		unless (null s) $ do