Add traceTc in tcSimplifyDefault

diff --git a/compiler/typecheck/TcSimplify.lhs b/compiler/typecheck/TcSimplify.lhs
index b771502..30718c2 100644 (file)
--- a/compiler/typecheck/TcSimplify.lhs
+++ b/compiler/typecheck/TcSimplify.lhs
@@ -2890,7 +2890,7 @@ tcSimplifyDefault theta
     if null irreds then
        returnM ()
     else
-       failM
+       traceTc (ptext SLIT("tcSimplifyDefault failing")) >> failM
   where
     doc = ptext SLIT("default declaration")
 \end{code}