Rethink filename encoding handling for display. Since filename encoding may or may not match locale settings, any attempt to decode filenames will fail for some files. So instead, do all output in binary mode.

Command/PreCommit.hs

@@ -34,7 +34,7 @@ perform pair@(file, _) = do
 	ok <- doCommand $ Command.Add.start pair
 	if ok
 		then return $ Just $ cleanup file
-		else error $ "failed to add " ++ filePathToString file ++ "; canceling commit"
+		else error $ "failed to add " ++ file ++ "; canceling commit"
 
 cleanup :: FilePath -> CommandCleanup
 cleanup file = do