error -> throw $ GMEProcess

Language/Haskell/GhcMod/Error.hs

@@ -126,12 +126,12 @@ gmeDoc e = case e of
         compsDoc sc = fsep $ punctuate comma $
                         map gmComponentNameDoc $ Set.toList sc
 
-    GMEProcess cmd args emsg -> let c = showCommandForUser cmd args in
+    GMEProcess _fn cmd args emsg -> let c = showCommandForUser cmd args in
         case emsg of
           Right err ->
              text (printf "Launching system command `%s` failed: " c)
                   <> gmeDoc err
-          Left (_out, _err, rv) -> text $
+          Left rv -> text $
              printf "Launching system command `%s` failed (exited with %d)" c rv
     GMENoCabalFile ->
         text "No cabal file found."

Language/Haskell/GhcMod/Output.hs

@@ -188,7 +188,7 @@ readProcessStderrChan' pute = go pute
      res <- waitForProcess h
      case res of
        ExitFailure rv ->
-           processFailedException "readProcessStderrChan" exe args rv
+           throw $ GMEProcess "readProcessStderrChan" exe args $ Left rv
        ExitSuccess ->
            return output
     where
@@ -204,9 +204,3 @@ withForkWait async body = do
     tid <- forkIO $ try (restore async) >>= putMVar waitVar
     let wait = takeMVar waitVar >>= either throwIO return
     restore (body wait) `onException` killThread tid
-
-processFailedException :: String -> String -> [String] -> Int -> IO a
-processFailedException fn exe args rv =
-      error $ concat [ fn, ": ", exe, " "
-                     , intercalate " " (map show args)
-                     , " (exit " ++ show rv ++ ")"]

Language/Haskell/GhcMod/PathsAndFiles.hs

@@ -35,7 +35,6 @@ import System.Process
 import System.Info.Extra
 
 import Language.Haskell.GhcMod.Types
-import Language.Haskell.GhcMod.Error
 import Language.Haskell.GhcMod.Caching
 import Language.Haskell.GhcMod.Output
 import qualified Language.Haskell.GhcMod.Utils as U

Language/Haskell/GhcMod/Types.hs

@@ -372,9 +372,9 @@ data GhcModError
   | GMECabalCompAssignment [(Either FilePath ModuleName, Set ChComponentName)]
   -- ^ Could not find a consistent component assignment for modules
 
-  | GMEProcess String [String] (Either (String, String, Int) GhcModError)
+  | GMEProcess String String [String] (Either Int GhcModError)
   -- ^ Launching an operating system process failed. Fields in
-  -- order: command, arguments, (stdout, stderr, exitcode)
+  -- order: function, command, arguments, (stdout, stderr, exitcode)
 
   | GMENoCabalFile
   -- ^ No cabal file found.

test/InfoSpec.hs

@@ -12,6 +12,7 @@ import System.Environment (getExecutablePath)
 import System.FilePath
 import Test.Hspec
 import TestUtils
+import Prelude
 
 spec :: Spec
 spec = do