Improve error message of :set in ghci (ticket #4190).

diff --git a/ghc/InteractiveUI.hs b/ghc/InteractiveUI.hs
index 278470f..ad46afb 100644 (file)
--- a/ghc/InteractiveUI.hs
+++ b/ghc/InteractiveUI.hs
@@ -1562,7 +1562,9 @@ newDynFlags minus_opts = do
       liftIO $ handleFlagWarnings dflags' warns
 
       if (not (null leftovers))
-        then ghcError $ errorsToGhcException leftovers
+        then ghcError . CmdLineError
+           $ "Some flags have not been recognized: "
+          ++ (concat . intersperse ", " $ map unLoc leftovers)
         else return ()
 
       new_pkgs <- setDynFlags dflags'