X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Ftypes%2FCoercion.lhs;h=770988da359ba9dcded1b1a78d5218c3e0c00c2f;hb=3b1438a9757639d7f37f10e1237e2369ca0ebe4a;hp=b157f95a6cbf020c3d1477d1acc1dc187b712710;hpb=17b297d97d327620ed6bfab942f8992b2446f1bf;p=ghc-hetmet.git

diff --git a/compiler/types/Coercion.lhs b/compiler/types/Coercion.lhs
index b157f95..770988d 100644
--- a/compiler/types/Coercion.lhs
+++ b/compiler/types/Coercion.lhs
@@ -12,11 +12,11 @@ The coercion kind constructor is a special TyCon that must always be saturated
   typeKind (symCoercion type) :: TyConApp CoercionTyCon{...} [type, type]
 
 \begin{code}
-{-# OPTIONS_GHC -w #-}
+{-# OPTIONS -w #-}
 -- The above warning supression flag is a temporary kludge.
 -- While working on this module you are encouraged to remove it and fix
 -- any warnings in the module. See
---     http://hackage.haskell.org/trac/ghc/wiki/WorkingConventions#Warnings
+--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
 -- for details
 
 module Coercion (
@@ -371,7 +371,10 @@ transCoercionTyCon =
   where
     composeCoercionKindsOf (co1:co2:rest)
       = ASSERT( null rest )
-        WARN( not (r1 `coreEqType` a2), text "Strange! Type mismatch in trans coercion, probably a bug")
+        WARN( not (r1 `coreEqType` a2), 
+              text "Strange! Type mismatch in trans coercion, probably a bug"
+              $$
+              ppr r1 <+> text "=/=" <+> ppr a2)
         (a1, r2)
       where
         (a1, r1) = coercionKind co1