anchor.diff:                  then Some path
                   else None) in
           match p with
  -        | Some f ->
  -            if !Options.debug <> []
  -            then Util.fprint1 "Opening file: %s\n" f;
  -            new System.IO.StreamReader(f)
  +        | Some f -> f
           | _ -> raise (Absyn.Syntax.Err("unable to open file"))
       with e -> raise (Absyn.Syntax.Err (Util.format2 "Unable to open file: %s\n%s\n" filename (e.ToString())))
   
  +let open_file (filename:string) =
  +  if !Options.debug <> []
  +  then Util.fprint1 "Opening file: %s\n" filename;
  +  new System.IO.StreamReader(filename)
   
   let read_build_config (filename:string) =
       let fail msg = raise (Absyn.Syntax.Err(Util.format2 "Could not parse a valid build configuration from %s; %s" filename msg)) in
  
positive.code: 
  let bc_start = "(*--build-config"
  let bc_end   = "--*)"
  let open_file (filename:string) =
      let include_path = Options.get_include_path() in
      try
          let p = Util.find_map include_path (fun p ->
  
negative.code: 
  (*
     Copyright 2008-2014 Nikhil Swamy and Microsoft Research
  
  