[project @ 1999-07-27 07:31:16 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcType.lhs

diff --git a/ghc/compiler/typecheck/TcType.lhs b/ghc/compiler/typecheck/TcType.lhs
index 95a5bdd..4f33951 100644 (file)
--- a/ghc/compiler/typecheck/TcType.lhs
+++ b/ghc/compiler/typecheck/TcType.lhs
@@ -312,8 +312,11 @@ zonkTcTyVars tyvars = mapNF_Tc zonkTcTyVar tyvars
 
 zonkTcTyVarBndr :: TcTyVar -> NF_TcM s TcTyVar
 zonkTcTyVarBndr tyvar
-  = zonkTcTyVar tyvar  `thenNF_Tc` \ (TyVarTy tyvar') ->
-    returnNF_Tc tyvar'
+  = zonkTcTyVar tyvar  `thenNF_Tc` \ ty ->
+    case ty of
+       TyVarTy tyvar' -> returnNF_Tc tyvar'
+       _              -> pprTrace "zonkTcTyVarBndr" (ppr tyvar <+> ppr ty) $
+                         returnNF_Tc tyvar
        
 zonkTcTyVar :: TcTyVar -> NF_TcM s TcType
 zonkTcTyVar tyvar = zonkTyVar (\ tv -> returnNF_Tc (TyVarTy tv)) tyvar