returnTc (tycon_name, SynTyDetails rhs_ty)
-tcTyDecl1 (TyData new_or_data context tycon_name _ con_decls _ derivings _ src_loc name1 name2)
+tcTyDecl1 (TyData new_or_data context tycon_name _ con_decls _ derivings src_loc name1 name2)
= tcLookupTyCon tycon_name `thenNF_Tc` \ tycon ->
let
tyvars = tyConTyVars tycon