Error using correct util and fix of documentation

src/bin/common/solving_loop.ml

@@ -51,7 +51,7 @@ let empty_solver_ctx = {
 }
 
 let unsupported_opt s =
-  Printer.print_wrn "unsupported option %S" s
+  Printer.print_smtlib_err "unsupported option %S" s
 
 let main () =
   let () = Dolmen_loop.Code.init [] in
@@ -417,8 +417,7 @@ let main () =
   let pp_reason_unknown fmt st =
     let err () =
       let msg = "Invalid (get-info :reason-unknown)" in
-      Printer.print_err "%s" msg;
-      Format.fprintf fmt "(error %S)" msg
+      Printer.fprint_smtlib_err fmt "%S" msg
     in
     match State.get partial_model_key st with
     | None ->

src/lib/util/printer.ml

@@ -382,9 +382,7 @@ let print_status_preprocess ?(validity_mode=true)
     ("Preprocessing","","fg_magenta") None
     time steps None
 
-let print_smtlib_err ?(flushed=true) s =
-  (* The smtlib error messages are printed on the regular output. *)
-  let fmt = Options.Output.get_fmt_regular () in
+let fprint_smtlib_err ?(flushed=true) fmt s =
   let k fmt =
     if flushed || Options.get_output_with_forced_flush () then
       Format.fprintf fmt "\")@."
@@ -393,3 +391,10 @@ let print_smtlib_err ?(flushed=true) s =
   in
   Format.fprintf fmt "(error \"";
   Format.kfprintf k fmt s
+
+let print_smtlib_err ?(flushed=true) s =
+  (* The smtlib error messages are printed on the regular output. *)
+  fprint_smtlib_err
+    ~flushed
+    (Options.Output.get_fmt_regular ())
+    s

src/lib/util/printer.mli

@@ -175,9 +175,15 @@ val print_status_preprocess :
   float option ->
   int option -> unit
 
-(** Print smtlib error message on the error formatter accessible with
-    {!val:Options.get_fmt_err} and set by default to stderr.
-    The err formatter is flushed after the print if flushed is set *)
+(** Print smtlib error message on the formatter in argument. *)
+val fprint_smtlib_err :
+  ?flushed:bool ->
+  Format.formatter ->
+  ('a, Format.formatter, unit) format -> 'a
+
+(** Print smtlib error message on the regular formatter, accessible with
+    {!val:Options.get_fmt_regular} and set by default to stdout.
+    The regular formatter is flushed after the print if flushed is set. *)
 val print_smtlib_err :
   ?flushed:bool ->
   ('a, Format.formatter, unit) format -> 'a