diff --git a/src/main/compile/helpers.ml b/src/main/compile/helpers.ml
index 11250cb73..a8ec052ae 100644
--- a/src/main/compile/helpers.ml
+++ b/src/main/compile/helpers.ml
@@ -24,11 +24,9 @@ let syntax_to_variant : s_syntax -> string option -> v_syntax result =
   | _ -> simple_fail "unrecognized parser"
 
 let parsify_pascaligo source =
-  let () = prerr_endline "Helpers.parsify_pascaligo: BEFORE" in
   let%bind raw =
     trace (simple_error "parsing") @@
     Parser.Pascaligo.parse_file source in
-  let () = prerr_endline "Helpers.parsify_pascaligo: AFTER" in
   let%bind simplified =
     trace (simple_error "simplifying") @@
       Simplify.Pascaligo.simpl_program raw
@@ -84,9 +82,7 @@ let parsify = fun (syntax : v_syntax) source_filename ->
     | Pascaligo -> ok parsify_pascaligo
     | Cameligo -> ok parsify_cameligo
     | ReasonLIGO -> ok parsify_reasonligo in
-  let () = prerr_endline "Helpers.parsify: BEFORE" in
   let%bind parsified = parsify source_filename in
-  let () = prerr_endline "Helpers.parsify: AFTER" in
   let%bind applied = Self_ast_simplified.all_program parsified in
   ok applied
 
diff --git a/src/passes/1-parser/pascaligo.ml b/src/passes/1-parser/pascaligo.ml
index 5f41853ba..c6eac2258 100644
--- a/src/passes/1-parser/pascaligo.ml
+++ b/src/passes/1-parser/pascaligo.ml
@@ -221,10 +221,8 @@ let parse_file (source: string) =
     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
-  let res = parse (module IO) thunk in
-  let () = prerr_endline "Pascaligo.parse_file: Leaving." in
-  res
+  let thunk () = Unit.apply instance Unit.parse_contract
+  in parse (module IO) thunk
 
 let parse_string (s: string) =
   let module IO =
diff --git a/src/passes/1-parser/shared/ParserUnit.ml b/src/passes/1-parser/shared/ParserUnit.ml
index 36af01395..ae03d0d32 100644
--- a/src/passes/1-parser/shared/ParserUnit.ml
+++ b/src/passes/1-parser/shared/ParserUnit.ml
@@ -70,8 +70,7 @@ module Make (Lexer: Lexer.S)
         ParserLog.mk_state ~offsets:IO.options#offsets
                            ~mode:IO.options#mode
                            ~buffer:output in
-      let close_all () =
-        lexer_inst.Lexer.close (); close_out stdout in
+      let close () = lexer_inst.Lexer.close () in
       let expr =
         try
           if IO.options#mono then
@@ -80,7 +79,7 @@ module Make (Lexer: Lexer.S)
             in Front.mono_expr tokeniser lexbuf
           else
             Front.incr_expr lexer_inst
-        with exn -> close_all (); raise exn in
+        with exn -> close (); raise exn in
       let () =
         if SSet.mem "ast-tokens" IO.options#verbose then
           begin
@@ -95,7 +94,7 @@ module Make (Lexer: Lexer.S)
             ParserLog.pp_expr state expr;
             Buffer.output_buffer stdout output
           end
-      in close_all (); Ok expr
+      in close (); Ok expr
 
     (* Parsing a contract *)
 
@@ -106,8 +105,7 @@ module Make (Lexer: Lexer.S)
         ParserLog.mk_state ~offsets:IO.options#offsets
                            ~mode:IO.options#mode
                            ~buffer:output in
-      let close_all () =
-        lexer_inst.Lexer.close (); close_out stdout in
+      let close () = lexer_inst.Lexer.close () in
       let ast =
         try
           if IO.options#mono then
@@ -116,7 +114,7 @@ module Make (Lexer: Lexer.S)
             in Front.mono_contract tokeniser lexbuf
           else
             Front.incr_contract lexer_inst
-        with exn -> close_all (); raise exn in
+        with exn -> close (); raise exn in
       let () =
         if SSet.mem "ast-tokens" IO.options#verbose then
           begin
@@ -131,7 +129,7 @@ module Make (Lexer: Lexer.S)
             ParserLog.pp_ast state ast;
             Buffer.output_buffer stdout output
           end
-      in close_all (); Ok ast
+      in close (); Ok ast
 
     (* Wrapper for the parsers above *)
 
diff --git a/src/passes/2-simplify/cameligo.ml b/src/passes/2-simplify/cameligo.ml
index 917d001bf..1e210880c 100644
--- a/src/passes/2-simplify/cameligo.ml
+++ b/src/passes/2-simplify/cameligo.ml
@@ -32,46 +32,48 @@ module Errors = struct
     in
     let data = [
       ("expected", fun () -> expected_name);
-      ("location" , fun () -> Format.asprintf "%a" Location.pp_lift @@ Raw.pattern_to_region actual)
-    ] in
-    error ~data title message
+      ("location",
+       fun () -> Format.asprintf "%a" Location.pp_lift @@
+                Raw.pattern_to_region actual)]
+    in error ~data title message
 
   let unsupported_let_in_function (patterns : Raw.pattern list) =
-    let title () = "unsupported 'let ... in' function" in
-    let message () = "defining functions via 'let ... in' is not supported yet" in
+    let title () = "" in
+    let message () = "\nDefining functions with \"let ... in\" \
+                      is not supported yet.\n" in
     let patterns_loc =
       List.fold_left (fun a p -> Region.cover a (Raw.pattern_to_region p))
         Region.ghost patterns in
     let data = [
-      ("location", fun () -> Format.asprintf "%a" Location.pp_lift @@ patterns_loc)
-    ] in
-    error ~data title message
+      ("location",
+       fun () -> Format.asprintf "%a" Location.pp_lift @@ patterns_loc)]
+    in error ~data title message
 
   let unknown_predefined_type name =
-    let title () = "type constants" in
+    let title () = "Type constants" in
     let message () =
-      Format.asprintf "unknown predefined type \"%s\"" name.Region.value in
+      Format.asprintf "Unknown predefined type \"%s\".\n"
+                      name.Region.value in
     let data = [
       ("location",
-       fun () -> Format.asprintf "%a" Location.pp_lift @@ name.Region.region)
-    ] in
-    error ~data title message
+       fun () -> Format.asprintf "%a" Location.pp_lift @@ name.Region.region)]
+    in error ~data title message
 
   let untyped_fun_param var =
-    let title () = "function parameter" in
+    let title () = "" in
     let message () =
-      Format.asprintf "untyped function parameters are not supported yet" in
+      Format.asprintf "\nUntyped function parameters \
+                       are not supported yet.\n" in
     let param_loc = var.Region.region in
     let data = [
       ("location",
-       fun () -> Format.asprintf "%a" Location.pp_lift @@ param_loc)
-    ] in
-    error ~data title message
+       fun () -> Format.asprintf "%a" Location.pp_lift @@ param_loc)]
+    in error ~data title message
 
   let unsupported_tuple_pattern p =
-    let title () = "tuple pattern" in
+    let title () = "" in
     let message () =
-      Format.asprintf "tuple patterns are not supported yet" in
+      Format.asprintf "\nTuple patterns are not supported yet.\n" in
     let pattern_loc = Raw.pattern_to_region p in
     let data = [
       ("location",
@@ -80,21 +82,20 @@ module Errors = struct
     error ~data title message
 
   let unsupported_cst_constr p =
-    let title () = "constant constructor" in
+    let title () = "" in
     let message () =
-      Format.asprintf "constant constructors are not supported yet" in
+      Format.asprintf "\nConstant constructors are not supported yet.\n" in
     let pattern_loc = Raw.pattern_to_region p in
     let data = [
       ("location",
-       fun () -> Format.asprintf "%a" Location.pp_lift @@ pattern_loc)
-    ] in
-    error ~data title message
-  
+       fun () -> Format.asprintf "%a" Location.pp_lift @@ pattern_loc)]
+    in error ~data title message
+
   let unsupported_non_var_pattern p =
-    let title () = "pattern is not a variable" in
+    let title () = "" in
     let message () =
-      Format.asprintf "non-variable patterns in constructors \
-                       are not supported yet" in
+      Format.asprintf "\nNon-variable patterns in constructors \
+                       are not supported yet.\n" in
     let pattern_loc = Raw.pattern_to_region p in
     let data = [
       ("location",
@@ -103,20 +104,20 @@ module Errors = struct
     error ~data title message
 
   let simplifying_expr t =
-    let title () = "simplifying expression" in
+    let title () = "Simplifying expression" in
     let message () = "" in
     let data = [
         ("expression" ,
          (** TODO: The labelled arguments should be flowing from the CLI. *)
        thunk @@ Parser.Cameligo.ParserLog.expr_to_string
-                 ~offsets:true ~mode:`Point t)
-    ] in
-    error ~data title message
+                 ~offsets:true ~mode:`Point t)]
+    in error ~data title message
 
   let only_constructors p =
-    let title () = "constructors in patterns" in
+    let title () = "" in
     let message () =
-      Format.asprintf "currently, only constructors are supported in patterns" in
+      Format.asprintf "\nCurrently, only constructors are \
+                       supported in patterns.\n" in
     let pattern_loc = Raw.pattern_to_region p in
     let data = [
       ("location",
@@ -125,18 +126,18 @@ module Errors = struct
     error ~data title message
 
   let unsupported_sugared_lists region =
-    let title () = "lists in patterns" in
+    let title () = "" in
     let message () =
-      Format.asprintf "currently, only empty lists and constructors (::) \
-                       are supported in patterns" in
+      Format.asprintf "\nCurrently, only empty lists and \
+                       constructors (::) \
+                       are supported in patterns.\n" in
     let data = [
       ("location",
-       fun () -> Format.asprintf "%a" Location.pp_lift @@ region)
-    ] in
-    error ~data title message
+       fun () -> Format.asprintf "%a" Location.pp_lift @@ region)]
+    in error ~data title message
 
   let corner_case description =
-    let title () = "corner case" in
+    let title () = "Corner case" in
     let message () = description in
     error title message
 
@@ -286,9 +287,9 @@ let rec simpl_expression :
   let simpl_update = fun (u:Raw.update Region.reg) ->
     let (u, loc) = r_split u in
     let (name, path) = simpl_path u.record in
-    let record = match path with 
+    let record = match path with
     | [] -> e_variable (Var.of_name name)
-    | _ -> e_accessor (e_variable (Var.of_name name)) path in 
+    | _ -> e_accessor (e_variable (Var.of_name name)) path in
     let updates = u.updates.value.ne_elements in
     let%bind updates' =
       let aux (f:Raw.field_assign Raw.reg) =
@@ -296,7 +297,7 @@ let rec simpl_expression :
         let%bind expr = simpl_expression f.field_expr in
         ok (f.field_name.value, expr)
       in
-      bind_map_list aux @@ npseq_to_list updates 
+      bind_map_list aux @@ npseq_to_list updates
     in
     return @@ e_update ~loc record updates'
   in
@@ -347,7 +348,7 @@ let rec simpl_expression :
         | hd :: tl ->
           e_let_in hd
           inline
-          (e_accessor rhs_b_expr [Access_tuple ((List.length prep_vars) - (List.length tl) - 1)])          
+          (e_accessor rhs_b_expr [Access_tuple ((List.length prep_vars) - (List.length tl) - 1)])
           (chain_let_in tl body)
         | [] -> body (* Precluded by corner case assertion above *)
       in
@@ -724,7 +725,7 @@ and simpl_declaration : Raw.declaration -> declaration Location.wrap list result
               match v_type with
               | Some v_type -> ok (to_option (simpl_type_expression v_type))
               | None -> ok None
-            in            
+            in
             let%bind simpl_rhs_expr = simpl_expression rhs_expr in
               ok @@ loc x @@ Declaration_constant (Var.of_name v.value, v_type_expression, inline, simpl_rhs_expr) )
           in let%bind variables = ok @@ npseq_to_list pt.value
@@ -825,9 +826,9 @@ and simpl_cases : type a . (Raw.pattern * a) list -> (a, unit) matching result =
     | PConstr v ->
        let const, pat_opt =
          match v with
-           PConstrApp {value; _} -> 
+           PConstrApp {value; _} ->
            (match value with
-           | constr, None ->              
+           | constr, None ->
               constr, Some (PVar {value = "unit"; region = Region.ghost})
            | _ -> value)
          | PSomeApp {value=region,pat; _} ->
diff --git a/src/passes/2-simplify/pascaligo.ml b/src/passes/2-simplify/pascaligo.ml
index 00b97ed7f..ce8f8c7be 100644
--- a/src/passes/2-simplify/pascaligo.ml
+++ b/src/passes/2-simplify/pascaligo.ml
@@ -68,9 +68,9 @@ let detect_free_variables (for_body : expression) (local_decl_names : expression
 
 module Errors = struct
   let unsupported_cst_constr p =
-    let title () = "constant constructor" in
+    let title () = "" in
     let message () =
-      Format.asprintf "constant constructors are not supported yet" in
+      Format.asprintf "\nConstant constructors are not supported yet.\n" in
     let pattern_loc = Raw.pattern_to_region p in
     let data = [
       ("location",
@@ -79,11 +79,11 @@ module Errors = struct
     error ~data title message
 
   let corner_case ~loc message =
-    let title () = "corner case" in
-    let content () = "We don't have a good error message for this case. \
+    let title () = "\nCorner case" in
+    let content () = "We do not have a good error message for this case. \
                       We are striving find ways to better report them and \
                       find the use-cases that generate them. \
-                      Please report this to the developers." in
+                      Please report this to the developers.\n" in
     let data = [
       ("location" , fun () -> loc) ;
       ("message" , fun () -> message) ;
@@ -91,9 +91,9 @@ module Errors = struct
     error ~data title content
 
   let unknown_predefined_type name =
-    let title () = "type constants" in
+    let title () = "\nType constants" in
     let message () =
-      Format.asprintf "unknown predefined type \"%s\"" name.Region.value in
+      Format.asprintf "Unknown predefined type \"%s\".\n" name.Region.value in
     let data = [
       ("location",
        fun () -> Format.asprintf "%a" Location.pp_lift @@ name.Region.region)
@@ -101,10 +101,10 @@ module Errors = struct
     error ~data title message
 
   let unsupported_non_var_pattern p =
-    let title () = "pattern is not a variable" in
+    let title () = "" in
     let message () =
-      Format.asprintf "non-variable patterns in constructors \
-                       are not supported yet" in
+      Format.asprintf "\nNon-variable patterns in constructors \
+                       are not supported yet.\n" in
     let pattern_loc = Raw.pattern_to_region p in
     let data = [
       ("location",
@@ -113,9 +113,10 @@ module Errors = struct
     error ~data title message
 
   let only_constructors p =
-    let title () = "constructors in patterns" in
+    let title () = "" in
     let message () =
-      Format.asprintf "currently, only constructors are supported in patterns" in
+      Format.asprintf "\nCurrently, only constructors \
+                       are supported in patterns.\n" in
     let pattern_loc = Raw.pattern_to_region p in
     let data = [
       ("location",
@@ -124,9 +125,9 @@ module Errors = struct
     error ~data title message
 
   let unsupported_tuple_pattern p =
-    let title () = "tuple pattern" in
+    let title () = "" in
     let message () =
-      Format.asprintf "tuple patterns are not supported yet" in
+      Format.asprintf "\nTuple patterns are not supported yet.\n" in
     let pattern_loc = Raw.pattern_to_region p in
     let data = [
       ("location",
@@ -139,10 +140,10 @@ module Errors = struct
     error ~data title message
 
   let unsupported_deep_Some_patterns pattern =
-    let title () = "option patterns" in
+    let title () = "" in
     let message () =
-      Format.asprintf "currently, only variables in Some constructors \
-                       in patterns are supported" in
+      Format.asprintf "\nCurrently, only variables in constructors \
+                       \"Some\" in patterns are supported.\n" in
     let pattern_loc = Raw.pattern_to_region pattern in
     let data = [
       ("location",
@@ -151,10 +152,10 @@ module Errors = struct
     error ~data title message
 
   let unsupported_deep_list_patterns cons =
-    let title () = "lists in patterns" in
+    let title () = "" in
     let message () =
-      Format.asprintf "currently, only empty lists and x::y \
-                       are supported in patterns" in
+      Format.asprintf "\nCurrently, only empty lists and x::y \
+                       are supported in patterns.\n" in
     let data = [
       ("location",
        fun () -> Format.asprintf "%a" Location.pp_lift @@ cons.Region.region)
@@ -164,7 +165,7 @@ module Errors = struct
   (* Logging *)
 
   let simplifying_instruction t =
-    let title () = "simplifiying instruction" in
+    let title () = "\nSimplifiying instruction" in
     let message () = "" in
     (** TODO: The labelled arguments should be flowing from the CLI. *)
     let data = [
@@ -1176,7 +1177,7 @@ and simpl_for_int : Raw.for_int -> (_ -> expression result) result = fun fi ->
             - references to the iterated value ==> variable `#COMPILER#elt_X`
        Note: In the case of an inner loop capturing variable from an outer loop
              the free variable name can be `#COMPILER#acc.Y` and because we do not
-             capture the accumulator record in the inner loop, we don't want to
+             capture the accumulator record in the inner loop, we do not want to
              generate `#COMPILER#acc.#COMPILER#acc.Y` but `#COMPILER#acc.Y`
 
     5) Append the return value to the body