From 0f53b896cbda2c2030e93f3afd07f0aa553487e0 Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Thu, 31 May 2001 11:25:51 +0000
Subject: [PATCH] [project @ 2001-05-31 11:25:51 by simonmar] If we can't read
 the old interface file for some reason (eg. it isn't there,
 or it has the wrong version), then output the error if
 -ddump-hi-diffs is on.  It used to be part of
 -ddump-rn-trace, but -ddump-hi-diffs seems more logical,
 since it covers all the other information about why a
 module is being recompiled.

---
 ghc/compiler/rename/Rename.lhs |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ghc/compiler/rename/Rename.lhs b/ghc/compiler/rename/Rename.lhs
index de1e0be..b8fce2e 100644
--- a/ghc/compiler/rename/Rename.lhs
+++ b/ghc/compiler/rename/Rename.lhs
@@ -413,7 +413,9 @@ checkOldIface ghci_mode dflags hit hst pcs iface_path source_unchanged maybe_ifa
           -> readIface iface_path	`thenRn` \ read_result ->
              case read_result of
                Left err -> -- Old interface file not found, or garbled; give up
-			   traceRn (text "Bad old interface file" $$ nest 4 err) `thenRn_`
+			   traceHiDiffsRn (
+				text "Cannot read old interface file:"
+			   	   $$ nest 4 err) `thenRn_`
 	                   returnRn (outOfDate, Nothing)
 
                Right parsed_iface
-- 
1.7.10.4