X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=ghc%2Fcompiler%2FdeSugar%2FDesugar.lhs;h=879058e0e6b4032a41db5777ed3e2da367a81e5f;hb=ca0b7c66f2e8e50f15a03c406408d9e86455f8eb;hp=d95ca8ceb62d2c3eb90b4b27588329717f805253;hpb=69e27f1d9d475a94e61fa54af40ac7be06d872ca;p=ghc-hetmet.git

diff --git a/ghc/compiler/deSugar/Desugar.lhs b/ghc/compiler/deSugar/Desugar.lhs
index d95ca8c..879058e 100644
--- a/ghc/compiler/deSugar/Desugar.lhs
+++ b/ghc/compiler/deSugar/Desugar.lhs
@@ -261,7 +261,7 @@ dsRule in_scope (L loc (HsRule name act vars lhs rhs))
     returnDs (fn, Rule name act tpl_vars args core_rhs)
   where
     tpl_vars = [var | RuleBndr (L _ var) <- vars]
-    all_vars = mkInScopeSet (in_scope `unionVarSet` mkVarSet tpl_vars)
+    all_vars = mkInScopeSet (extendVarSetList in_scope tpl_vars)
 
 ds_lhs all_vars lhs
   = let