Make sure backtraces are propagated

spectec/src/backend-interpreter/runner.ml

@@ -265,10 +265,11 @@ let parse_file name parser_ file =
   try
     parser_ file
   with e ->
+    let bt = Printexc.get_raw_backtrace () in
     print_endline ("- Failed to parse " ^ name ^ "\n");
     log ("- Failed to parse %s\n") name;
     num_parse_fail := !num_parse_fail + 1;
-    raise e
+    Printexc.raise_with_backtrace e bt
 
 
 (** Runner **)

spectec/src/il/valid.ml

@@ -449,8 +449,9 @@ try
     equiv_typ env t2 t e.at;
     sub_typ env t1 t2 e.at
 with exn ->
+  let bt = Printexc.get_raw_backtrace () in
   Printf.eprintf "[valid_exp] %s\n%!" (Debug.il_exp e);
-  raise exn
+  Printexc.raise_with_backtrace exn bt
 
 
 and valid_expmix env mixop e (mixop', t) at =

spectec/src/util/debug_log.ml

@@ -14,8 +14,9 @@ let log_at (type a) label at (arg_f : unit -> string) (res_f : a -> string) (f :
   Printf.eprintf "[%s%s] %s\n%!" label ats arg;
   match f () with
   | exception exn ->
+    let bt = Printexc.get_raw_backtrace () in
     Printf.eprintf "[%s%s] %s => raise %s\n%!" label ats arg (Printexc.to_string exn);
-    raise exn
+    Printexc.raise_with_backtrace exn bt
   | x ->
     let res = res_f x in
     if res <> "" then Printf.eprintf "[%s%s] %s => %s\n%!" label ats arg res;