diff --git a/src/bin/expect_tests/lexer_tests.ml b/src/bin/expect_tests/lexer_tests.ml
index 0b60086ce..4768d90c2 100644
--- a/src/bin/expect_tests/lexer_tests.ml
+++ b/src/bin/expect_tests/lexer_tests.ml
@@ -6,7 +6,7 @@ let%expect_test _ =
 ligo: : Lexical error in file "broken_string.ligo", line 1, characters 18-19:
       The string starting here is interrupted by a line break.
       Hint: Remove the break, close the string before or insert a backslash.
-       {"parser_loc":"in file \"broken_string.ligo\", line 1, characters 18-19"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -20,10 +20,10 @@ ligo: : Lexical error in file "broken_string.ligo", line 1, characters 18-19:
 
     run_ligo_bad [ "compile-contract" ; "../../test/lexer/broken_string.mligo" ; "main" ] ;
   [%expect {| 
-ligo: : Lexical error at line 1, characters 8-9:
+ligo: : Lexical error in file "broken_string.mligo", line 1, characters 8-9:
       The string starting here is interrupted by a line break.
       Hint: Remove the break, close the string before or insert a backslash.
-       {"parser_loc":"in file \"broken_string.mligo\", line 1, characters 8-9"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -57,7 +57,7 @@ run_ligo_bad [ "compile-contract" ; "../../test/lexer/negative_byte_sequence.lig
 ligo: : Lexical error in file "negative_byte_sequence.ligo", line 1, characters 18-23:
       Negative byte sequence.
       Hint: Remove the leading minus sign.
-       {"parser_loc":"in file \"negative_byte_sequence.ligo\", line 1, characters 18-23"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -71,10 +71,10 @@ ligo: : Lexical error in file "negative_byte_sequence.ligo", line 1, characters
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/negative_byte_sequence.mligo" ; "main" ] ;
   [%expect {| 
-ligo: : Lexical error at line 1, characters 8-13:
+ligo: : Lexical error in file "negative_byte_sequence.mligo", line 1, characters 8-13:
       Negative byte sequence.
       Hint: Remove the leading minus sign.
-       {"parser_loc":"in file \"negative_byte_sequence.mligo\", line 1, characters 8-13"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -108,7 +108,7 @@ ligo: : Lexical error at line 1, characters 8-13:
 ligo: : Lexical error in file "reserved_name.ligo", line 1, characters 4-13:
       Reserved name: arguments.
       Hint: Change the name.
-       {"parser_loc":"in file \"reserved_name.ligo\", line 1, characters 4-13"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -139,10 +139,10 @@ ligo: : Lexical error at line 1, characters 4-7:
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/reserved_name.mligo" ; "main" ] ;
   [%expect {| 
-ligo: : Lexical error at line 1, characters 4-10:
+ligo: : Lexical error in file "reserved_name.mligo", line 1, characters 4-10:
       Reserved name: object.
       Hint: Change the name.
-       {"parser_loc":"in file \"reserved_name.mligo\", line 1, characters 4-10"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -158,7 +158,7 @@ run_ligo_bad [ "compile-contract" ; "../../test/lexer/unexpected_character.ligo"
   [%expect {| 
 ligo: : Lexical error in file "unexpected_character.ligo", line 1, characters 18-19:
       Unexpected character '\239'.
-       {"parser_loc":"in file \"unexpected_character.ligo\", line 1, characters 18-19"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -172,9 +172,9 @@ ligo: : Lexical error in file "unexpected_character.ligo", line 1, characters 18
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/unexpected_character.mligo" ; "main" ] ;
   [%expect {| 
-ligo: : Lexical error at line 1, characters 8-9:
+ligo: : Lexical error in file "unexpected_character.mligo", line 1, characters 8-9:
       Unexpected character '\239'.
-       {"parser_loc":"in file \"unexpected_character.mligo\", line 1, characters 8-9"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -204,10 +204,10 @@ ligo: : Lexical error at line 1, characters 8-9:
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/unterminated_comment.mligo" ; "main" ] ;
   [%expect {| 
-ligo: : Lexical error at line 1, characters 0-2:
+ligo: : Lexical error in file "unterminated_comment.mligo", line 1, characters 0-2:
       Unterminated comment.
       Hint: Close with "*)".
-       {"parser_loc":"in file \"unterminated_comment.mligo\", line 1, characters 0-2"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -224,7 +224,7 @@ run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_symbol.ligo" ; "ma
 ligo: : Lexical error in file "invalid_symbol.ligo", line 1, characters 17-20:
       Invalid symbol.
       Hint: Check the LIGO syntax you use.
-       {"parser_loc":"in file \"invalid_symbol.ligo\", line 1, characters 17-20"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -238,10 +238,10 @@ ligo: : Lexical error in file "invalid_symbol.ligo", line 1, characters 17-20:
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_symbol.mligo" ; "main" ] ;
   [%expect {| 
-ligo: : Lexical error at line 1, characters 10-13:
+ligo: : Lexical error in file "invalid_symbol.mligo", line 1, characters 10-13:
       Invalid symbol.
       Hint: Check the LIGO syntax you use.
-       {"parser_loc":"in file \"invalid_symbol.mligo\", line 1, characters 10-13"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -275,7 +275,7 @@ ligo: : Lexical error at line 1, characters 10-11:
 ligo: : Lexical error in file "missing_break.ligo", line 1, characters 18-18:
       Missing break.
       Hint: Insert some space.
-       {"parser_loc":"in file \"missing_break.ligo\", line 1, characters 18-18"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -289,10 +289,10 @@ ligo: : Lexical error in file "missing_break.ligo", line 1, characters 18-18:
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/missing_break.mligo" ; "main" ] ;
   [%expect {| 
-ligo: : Lexical error at line 1, characters 11-11:
+ligo: : Lexical error in file "missing_break.mligo", line 1, characters 11-11:
       Missing break.
       Hint: Insert some space.
-       {"parser_loc":"in file \"missing_break.mligo\", line 1, characters 11-11"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -326,7 +326,7 @@ run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_character_in_strin
 ligo: : Lexical error in file "invalid_character_in_string.ligo", line 1, characters 19-20:
       Invalid character in string.
       Hint: Remove or replace the character.
-       {"parser_loc":"in file \"invalid_character_in_string.ligo\", line 1, characters 19-20"}
+       {}
 
 
  If you're not sure how to fix this error, you can
@@ -340,10 +340,10 @@ ligo: : Lexical error in file "invalid_character_in_string.ligo", line 1, charac
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_character_in_string.mligo" ; "main" ] ;
   [%expect {| 
-ligo: : Lexical error at line 1, characters 9-10:
+ligo: : Lexical error in file "invalid_character_in_string.mligo", line 1, characters 9-10:
       Invalid character in string.
       Hint: Remove or replace the character.
-       {"parser_loc":"in file \"invalid_character_in_string.mligo\", line 1, characters 9-10"}
+       {}
 
 
  If you're not sure how to fix this error, you can
diff --git a/src/bin/expect_tests/syntax_error_tests.ml b/src/bin/expect_tests/syntax_error_tests.ml
index 0d75b8c47..d3a735c3f 100644
--- a/src/bin/expect_tests/syntax_error_tests.ml
+++ b/src/bin/expect_tests/syntax_error_tests.ml
@@ -4,7 +4,7 @@ let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_syntax.ligo" ; "main" ] ;
   [%expect {|
     ligo: : Parse error in file "error_syntax.ligo", line 1, characters 16-17, after "bar" and before "-".
-           {"parser_loc":"in file \"error_syntax.ligo\", line 1, characters 16-17"}
+           {}
 
 
      If you're not sure how to fix this error, you can
diff --git a/src/passes/1-parser/cameligo.ml b/src/passes/1-parser/cameligo.ml
index cf9ca207f..e9107b8c6 100644
--- a/src/passes/1-parser/cameligo.ml
+++ b/src/passes/1-parser/cameligo.ml
@@ -1,11 +1,10 @@
-open Trace
-
-module AST = Parser_cameligo.AST
+module AST      = Parser_cameligo.AST
 module LexToken = Parser_cameligo.LexToken
-module Lexer = Lexer.Make(LexToken)
-module Scoping = Parser_cameligo.Scoping
-module Region = Simple_utils.Region
-module ParErr = Parser_cameligo.ParErr
+module Lexer    = Lexer.Make(LexToken)
+module Scoping  = Parser_cameligo.Scoping
+module Region   = Simple_utils.Region
+module ParErr   = Parser_cameligo.ParErr
+module SSet     = Utils.String.Set
 
 (* Mock IOs TODO: Fill them with CLI options *)
 
@@ -19,9 +18,8 @@ module PreIO =
   struct
     let ext = ".ligo"
     let pre_options =
-      EvalOpt.make ~input:None
-                   ~libs:[]
-                   ~verbose:Utils.String.Set.empty
+      EvalOpt.make ~libs:[]
+                   ~verbose:SSet.empty
                    ~offsets:true
                    ~mode:`Point
                    ~cmd:EvalOpt.Quiet
@@ -47,72 +45,32 @@ module PreUnit =
 
 module Errors =
   struct
-    let reserved_name Region.{value; region} =
-      let title () = Printf.sprintf "\nReserved name \"%s\"" value in
-      let message () = "" in
-      let data = [
-        ("location",
-         fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
-      in error ~data title message
+    (* let data =
+         [("location",
+           fun () -> Format.asprintf "%a" Location.pp_lift @@ loc)]
+     *)
 
-    let duplicate_variant Region.{value; region} =
-      let title () =
-        Printf.sprintf "\nDuplicate variant \"%s\" in this \
-                        type declaration" value in
-      let message () = "" in
-      let data = [
-        ("location",
-         fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
-      in error ~data title message
-
-    let non_linear_pattern Region.{value; region} =
-      let title () =
-        Printf.sprintf "\nRepeated variable \"%s\" in this pattern" value in
-      let message () = "" in
-      let data = [
-        ("location",
-         fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
-      in error ~data title message
-
-    let duplicate_field Region.{value; region} =
-      let title () =
-        Printf.sprintf "\nDuplicate field name \"%s\" \
-                        in this record declaration" value in
-      let message () = "" in
-      let data = [
-        ("location",
-         fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
-      in error ~data title message
-
-    let parser_error Region.{value; region} =
+    let generic message =
       let title () = ""
-      and message () = value
-      and loc = region in
-      let data =
-        [("parser_loc",
-          fun () -> Format.asprintf "%a" Location.pp_lift @@ loc)]
-      in error ~data title message
+      and message () = message.Region.value
+      in Trace.error ~data:[] title message
 
-    let lexer_error (e: Lexer.error AST.reg) =
-      let title () = "\nLexer error" in
-      let message () = Lexer.error_to_string e.value in
-      let data = [
-          ("parser_loc",
-           fun () -> Format.asprintf "%a" Location.pp_lift @@ e.region)]
-      in error ~data title message
   end
 
 let parse (module IO : IO) parser =
   let module Unit = PreUnit (IO) in
-  let mk_error error =
+  let local_fail error =
     Unit.format_error ~offsets:IO.options#offsets
-                      IO.options#mode error in
+                      IO.options#mode error
+    |> Errors.generic |> Trace.fail in
   match parser () with
-    (* Scoping errors *)
+    Stdlib.Ok semantic_value -> Trace.ok semantic_value
 
-    Stdlib.Ok semantic_value -> ok semantic_value
-  | Stdlib.Error error -> fail @@ Errors.parser_error error
-  | exception Lexer.Error e -> fail @@ Errors.lexer_error e
+  (* Lexing and parsing errors *)
+
+  | Stdlib.Error error ->
+     Trace.fail @@ Errors.generic error
+  (* Scoping errors *)
 
   | exception Scoping.Error (Scoping.Reserved_name name) ->
       let token =
@@ -122,18 +80,15 @@ let parse (module IO : IO) parser =
             reserved name for the lexer. *)
          Stdlib.Error _ -> assert false
        | Ok invalid ->
-          let point =
-            "Reserved name.\nHint: Change the name.\n", None, invalid
-          in fail @@ Errors.reserved_name @@ mk_error point)
+          local_fail
+            ("Reserved name.\nHint: Change the name.\n", None, invalid))
 
   | exception Scoping.Error (Scoping.Duplicate_variant name) ->
       let token =
-        Lexer.Token.mk_constr name.Region.value name.Region.region in
-      let point =
-        "Duplicate constructor in this sum type declaration.\n\
-         Hint: Change the constructor.\n",
-        None, token
-      in fail @@ Errors.duplicate_variant @@ mk_error point
+        Lexer.Token.mk_constr name.Region.value name.Region.region
+      in local_fail
+           ("Duplicate constructor in this sum type declaration.\n\
+             Hint: Change the constructor.\n", None, token)
 
   | exception Scoping.Error (Scoping.Non_linear_pattern var) ->
       let token =
@@ -143,11 +98,10 @@ let parse (module IO : IO) parser =
             reserved name for the lexer. *)
          Stdlib.Error _ -> assert false
        | Ok invalid ->
-           let point =
-             "Repeated variable in this pattern.\n\
-              Hint: Change the name.\n",
-             None, invalid
-           in fail @@ Errors.non_linear_pattern @@ mk_error point)
+           local_fail
+             ("Repeated variable in this pattern.\n\
+               Hint: Change the name.\n",
+              None, invalid))
 
   | exception Scoping.Error (Scoping.Duplicate_field name) ->
       let token =
@@ -157,60 +111,76 @@ let parse (module IO : IO) parser =
             reserved name for the lexer. *)
          Stdlib.Error _ -> assert false
        | Ok invalid ->
-           let point =
-             "Duplicate field name in this record declaration.\n\
-              Hint: Change the name.\n",
-             None, invalid
-           in fail @@ Errors.duplicate_field @@ mk_error point)
+           local_fail
+             ("Duplicate field name in this record declaration.\n\
+               Hint: Change the name.\n",
+              None, invalid))
 
 let parse_file (source: string) =
   let module IO =
     struct
       let ext = PreIO.ext
-      let options = PreIO.pre_options ~expr:false
+      let options =
+        PreIO.pre_options ~input:(Some source) ~expr:false
     end in
+  let lib_path =
+    match IO.options#libs with
+      [] -> ""
+    | libs -> let mk_I dir path = Printf.sprintf " -I %s%s" dir path
+             in List.fold_right mk_I libs "" in
+  let prefix =
+    match IO.options#input with
+      None | Some "-" -> "temp"
+    | Some file -> Filename.(file |> basename |> remove_extension) in
+  let suffix = ".pp" ^ IO.ext in
   let pp_input =
-    let prefix = Filename.(source |> basename |> remove_extension)
-    and suffix = ".pp.ligo"
-    in prefix ^ suffix in
-  let cpp_cmd = Printf.sprintf "cpp -traditional-cpp %s > %s"
-                               source pp_input in
+    if   SSet.mem "cpp" IO.options#verbose
+    then prefix ^ suffix
+    else let pp_input, pp_out =
+           Filename.open_temp_file prefix suffix
+         in close_out pp_out; pp_input in
+  let cpp_cmd =
+    match IO.options#input with
+      None | Some "-" ->
+        Printf.sprintf "cpp -traditional-cpp%s - > %s"
+                       lib_path pp_input
+    | Some file ->
+        Printf.sprintf "cpp -traditional-cpp%s %s > %s"
+                       lib_path file pp_input in
+  let open Trace in
   let%bind () = sys_command cpp_cmd in
-  let%bind channel =
-    generic_try (simple_error "Error when opening file") @@
-    (fun () -> open_in pp_input) in
   let module Unit = PreUnit (IO) in
   let instance =
-    match Lexer.open_token_stream (Lexer.Channel channel) with
+    match Lexer.open_token_stream (Lexer.File pp_input) with
       Ok instance -> instance
     | Stdlib.Error _ -> assert false (* No file opening *) in
-  let thunk () = Unit.apply instance Unit.parse_contract in
-  parse (module IO) thunk
+  let thunk () = Unit.apply instance Unit.parse_contract
+  in parse (module IO) thunk
 
 let parse_string (s: string) =
   let module IO =
     struct
       let ext = PreIO.ext
-      let options = PreIO.pre_options ~expr:false
+      let options = PreIO.pre_options ~input:None ~expr:false
     end in
   let module Unit = PreUnit (IO) in
   let instance =
     match Lexer.open_token_stream (Lexer.String s) with
       Ok instance -> instance
     | Stdlib.Error _ -> assert false (* No file opening *) in
-  let thunk () = Unit.apply instance Unit.parse_contract in
-  parse (module IO) thunk
+  let thunk () = Unit.apply instance Unit.parse_contract
+  in parse (module IO) thunk
 
 let parse_expression (s: string)  =
   let module IO =
     struct
       let ext = PreIO.ext
-      let options = PreIO.pre_options ~expr:true
+      let options = PreIO.pre_options ~input:None ~expr:true
     end in
   let module Unit = PreUnit (IO) in
   let instance =
     match Lexer.open_token_stream (Lexer.String s) with
       Ok instance -> instance
     | Stdlib.Error _ -> assert false (* No file opening *) in
-  let thunk () = Unit.apply instance Unit.parse_expr in
-  parse (module IO) thunk
+  let thunk () = Unit.apply instance Unit.parse_expr
+  in parse (module IO) thunk
diff --git a/src/passes/1-parser/cameligo/Parser.mly b/src/passes/1-parser/cameligo/Parser.mly
index 08c267a13..9a2d0870c 100644
--- a/src/passes/1-parser/cameligo/Parser.mly
+++ b/src/passes/1-parser/cameligo/Parser.mly
@@ -217,6 +217,7 @@ let_declaration:
 
 let_binding:
   "<ident>" nseq(sub_irrefutable) type_annotation? "=" expr {
+    Scoping.check_reserved_name $1;
     let binders = Utils.nseq_cons (PVar $1) $2 in
     Utils.nseq_iter Scoping.check_pattern binders;
     {binders; lhs_type=$3; eq=$4; let_rhs=$5}
diff --git a/src/passes/1-parser/cameligo/Scoping.ml b/src/passes/1-parser/cameligo/Scoping.ml
index 5f45c643b..483262deb 100644
--- a/src/passes/1-parser/cameligo/Scoping.ml
+++ b/src/passes/1-parser/cameligo/Scoping.ml
@@ -31,19 +31,30 @@ module VarSet = Set.Make (Ord)
 let reserved =
   let open SSet in
   empty
+  |> add "abs"
+  |> add "address"
+  |> add "amount"
   |> add "assert"
   |> add "balance"
-  |> add "time"
-  |> add "amount"
-  |> add "gas"
-  |> add "sender"
-  |> add "source"
-  |> add "failwith"
+  |> add "black2b"
+  |> add "check"
   |> add "continue"
-  |> add "stop"
+  |> add "failwith"
+  |> add "gas"
+  |> add "hash"
+  |> add "hash_key"
+  |> add "implicit_account"
   |> add "int"
-  |> add "abs"
+  |> add "pack"
+  |> add "self_address"
+  |> add "sender"
+  |> add "sha256"
+  |> add "sha512"
+  |> add "source"
+  |> add "stop"
+  |> add "time"
   |> add "unit"
+  |> add "unpack"
 
 let check_reserved_names vars =
   let is_reserved elt = SSet.mem elt.value reserved in
diff --git a/src/passes/1-parser/pascaligo.ml b/src/passes/1-parser/pascaligo.ml
index c6eac2258..07c17a69b 100644
--- a/src/passes/1-parser/pascaligo.ml
+++ b/src/passes/1-parser/pascaligo.ml
@@ -19,7 +19,7 @@ module PreIO =
     let ext = ".ligo"
     let pre_options =
       EvalOpt.make ~libs:[]
-                   ~verbose:(SSet.singleton "cpp")   (* TODO (Debug) *)
+                   ~verbose:SSet.empty
                    ~offsets:true
                    ~mode:`Point
                    ~cmd:EvalOpt.Quiet
@@ -45,81 +45,32 @@ module PreUnit =
 
 module Errors =
   struct
-    let reserved_name Region.{value; region} =
-      let title () = Printf.sprintf "\nReserved name \"%s\"" value in
-      let message () = "" in
-      let data = [
-        ("location",
-         fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
-      in Trace.error ~data title message
+    (* let data =
+         [("location",
+           fun () -> Format.asprintf "%a" Location.pp_lift @@ loc)]
+     *)
 
-    let duplicate_parameter Region.{value; region} =
-      let title () =
-        Printf.sprintf "\nDuplicate parameter \"%s\"" value in
-      let message () = "" in
-      let data = [
-        ("location",
-         fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
-      in Trace.error ~data title message
-
-    let duplicate_variant Region.{value; region} =
-      let title () =
-        Printf.sprintf "\nDuplicate variant \"%s\" in this \
-                        type declaration" value in
-      let message () = "" in
-      let data = [
-        ("location",
-         fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
-      in Trace.error ~data title message
-
-    let non_linear_pattern Region.{value; region} =
-      let title () =
-        Printf.sprintf "\nRepeated variable \"%s\" in this pattern" value in
-      let message () = "" in
-      let data = [
-        ("location",
-         fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
-      in Trace.error ~data title message
-
-    let duplicate_field Region.{value; region} =
-      let title () =
-        Printf.sprintf "\nDuplicate field name \"%s\" \
-                        in this record declaration" value in
-      let message () = "" in
-      let data = [
-        ("location",
-         fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
-      in Trace.error ~data title message
-
-    let parser_error Region.{value; region} =
+    let generic message =
       let title () = ""
-      and message () = value
-      and loc = region in
-      let data =
-        [("parser_loc",
-          fun () -> Format.asprintf "%a" Location.pp_lift @@ loc)]
-      in Trace.error ~data title message
+      and message () = message.Region.value
+      in Trace.error ~data:[] title message
 
-    let lexer_error (e: Lexer.error AST.reg) =
-      let title () = "\nLexer error" in
-      let message () = Lexer.error_to_string e.value in
-      let data = [
-          ("parser_loc",
-           fun () -> Format.asprintf "%a" Location.pp_lift @@ e.region)]
-      in Trace.error ~data title message
   end
 
 let parse (module IO : IO) parser =
   let module Unit = PreUnit (IO) in
-  let mk_error error =
+  let local_fail error =
     Unit.format_error ~offsets:IO.options#offsets
-                      IO.options#mode error in
+                      IO.options#mode error
+    |> Errors.generic |> Trace.fail in
   match parser () with
-    (* Scoping errors *)
-
     Stdlib.Ok semantic_value -> Trace.ok semantic_value
-  | Stdlib.Error error -> Trace.fail @@ Errors.parser_error error
-  | exception Lexer.Error e -> Trace.fail @@ Errors.lexer_error e
+
+  (* Lexing and parsing errors *)
+
+  | Stdlib.Error error ->
+     Trace.fail @@ Errors.generic error
+  (* Scoping errors *)
 
   | exception Scoping.Error (Scoping.Reserved_name name) ->
       let token =
@@ -129,9 +80,8 @@ let parse (module IO : IO) parser =
             reserved name for the lexer. *)
          Stdlib.Error _ -> assert false
        | Ok invalid ->
-          let point =
-            "Reserved name.\nHint: Change the name.\n", None, invalid
-          in Trace.fail @@ Errors.reserved_name @@ mk_error point)
+          local_fail
+            ("Reserved name.\nHint: Change the name.\n", None, invalid))
 
   | exception Scoping.Error (Scoping.Duplicate_parameter name) ->
       let token =
@@ -141,19 +91,16 @@ let parse (module IO : IO) parser =
             reserved name for the lexer. *)
          Stdlib.Error _ -> assert false
        | Ok invalid ->
-          let point =
-            "Duplicate parameter.\nHint: Change the name.\n",
-            None, invalid
-          in Trace.fail @@ Errors.duplicate_parameter @@ mk_error point)
+           local_fail
+             ("Duplicate parameter.\nHint: Change the name.\n",
+              None, invalid))
 
   | exception Scoping.Error (Scoping.Duplicate_variant name) ->
       let token =
-        Lexer.Token.mk_constr name.Region.value name.Region.region in
-      let point =
-        "Duplicate constructor in this sum type declaration.\n\
-         Hint: Change the constructor.\n",
-        None, token
-      in Trace.fail @@ Errors.duplicate_variant @@ mk_error point
+        Lexer.Token.mk_constr name.Region.value name.Region.region
+      in local_fail
+           ("Duplicate constructor in this sum type declaration.\n\
+             Hint: Change the constructor.\n", None, token)
 
   | exception Scoping.Error (Scoping.Non_linear_pattern var) ->
       let token =
@@ -163,11 +110,10 @@ let parse (module IO : IO) parser =
             reserved name for the lexer. *)
          Stdlib.Error _ -> assert false
        | Ok invalid ->
-           let point =
-             "Repeated variable in this pattern.\n\
-              Hint: Change the name.\n",
-             None, invalid
-           in Trace.fail @@ Errors.non_linear_pattern @@ mk_error point)
+           local_fail
+             ("Repeated variable in this pattern.\n\
+               Hint: Change the name.\n",
+              None, invalid))
 
   | exception Scoping.Error (Scoping.Duplicate_field name) ->
       let token =
@@ -177,11 +123,10 @@ let parse (module IO : IO) parser =
             reserved name for the lexer. *)
          Stdlib.Error _ -> assert false
        | Ok invalid ->
-           let point =
-             "Duplicate field name in this record declaration.\n\
-              Hint: Change the name.\n",
-             None, invalid
-           in Trace.fail @@ Errors.duplicate_field @@ mk_error point)
+           local_fail
+             ("Duplicate field name in this record declaration.\n\
+               Hint: Change the name.\n",
+              None, invalid))
 
 let parse_file (source: string) =
   let module IO =
diff --git a/src/passes/1-parser/shared/Lexer.mll b/src/passes/1-parser/shared/Lexer.mll
index e9d04ac0b..f39bff7ac 100644
--- a/src/passes/1-parser/shared/Lexer.mll
+++ b/src/passes/1-parser/shared/Lexer.mll
@@ -980,7 +980,7 @@ let open_token_stream input =
         with
           Sys_error msg -> Stdlib.Error (File_opening msg))
     | String s ->
-       Ok (Lexing.from_string s, fun () -> ())
+        Ok (Lexing.from_string s, fun () -> ())
     | Channel chan ->
         let close () = close_in chan in
         Ok (Lexing.from_channel chan, close)