X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=compiler%2Ftypecheck%2FTcMType.lhs;h=11ec9d9232c4313889319aa5f5a34276e8de8085;hb=1525a5819aa3a6eae8d8b05cfe348a2384da0c84;hp=fe51df121b681fa9d8b6d96cba5a792bb78a916b;hpb=af20907ae1c9901b457cbab57e9d533e66e5aa07;p=ghc-hetmet.git

diff --git a/compiler/typecheck/TcMType.lhs b/compiler/typecheck/TcMType.lhs
index fe51df1..11ec9d9 100644
--- a/compiler/typecheck/TcMType.lhs
+++ b/compiler/typecheck/TcMType.lhs
@@ -200,9 +200,13 @@ newMetaTyVar box_info kind
  	; ref <- newMutVar Flexi ;
 	; let name = mkSysTvName uniq fs 
 	      fs = case box_info of
-			BoxTv   -> FSLIT("bx")
+			BoxTv   -> FSLIT("t")
 			TauTv   -> FSLIT("t")
 			SigTv _ -> FSLIT("a")
+		-- We give BoxTv and TauTv the same string, because
+		-- otherwise we get user-visible differences in error
+		-- messages, which are confusing.  If you want to see
+		-- the box_info of each tyvar, use -dppr-debug
 	; return (mkTcTyVar name kind (MetaTv box_info ref)) }
 
 instMetaTyVar :: BoxInfo -> TyVar -> TcM TcTyVar