anchor.diff:  module U_Syntax = FStar.Syntax.Syntax
   module F_Syntax = FStar.Absyn.Syntax
   let detect_dependencies_with_first_interactive_chunk () =
  - try
  -     let fail msg = 
  -        if (Options.universes())
  -        then raise (U_Syntax.Err msg)
  -        else raise (F_Syntax.Err msg) in
  +  let failr msg r =
  +    if Options.universes()
  +    then FStar.TypeChecker.Errors.warn r msg
  +    else FStar.Tc.Errors.warn r msg;
  +    exit 1
  +  in
  +  let fail msg = failr msg Range.dummyRange in
  +  let parse_msg = "Dependency analysis may not be correct because the file failed to parse: " in
  +  try
         match find_initial_module_name () with
         | None ->
           fail "No initial module directive found\n"
  
positive.code:           | Some (None, None) ->
                failwith "impossible"
  
   with 
      | U_Syntax.Error(msg, r) -> 
        FStar.TypeChecker.Errors.warn r msg;
        FStar.TypeChecker.Errors.warn r ("Dependency analysis may not be correct because the file failed to parse: "^msg);
        [] 
      | F_Syntax.Error(msg, r) -> 
        FStar.Tc.Errors.warn r msg;
        FStar.Tc.Errors.warn r ("Dependency analysis may not be correct because the file failed to parse: "^msg);
        [] 
      | U_Syntax.Err msg
      | F_Syntax.Err msg -> 
        FStar.Tc.Errors.warn Range.dummyRange ("Dependency analysis may not be correct because the file failed to parse: " ^msg);
        []
            
  
  (******************************************************************************************)
  (* The main interactive loop *)
  (******************************************************************************************)
  let interactive_mode (env:'env) (initial_mod:'modul) (tc:interactive_tc<'env,'modul>) = 
    if Option.isSome (Options.codegen()) then
      (Util.print_warning "code-generation is not supported in interactive mode, ignoring the codegen flag");
      let rec go (stack:stack<'env,'modul>) (curmod:'modul) (env:'env) = begin
  
negative.code:             Util.print1 "%s\n" fail;
              let env = tc.reset_mark env_mark in
              go stack curmod env in
  
            let env_mark = tc.mark env in
            let res = tc.check_frag env_mark curmod text in begin
              match res with
  