P2p: better logging on failing "Swap".

src/node/net/p2p_connection_pool.ml

@@ -1031,8 +1031,13 @@ and swap pool conn current_peer_id new_point =
   | Error err -> begin
       pool.latest_accepted_swap <- pool.latest_succesfull_swap ;
       log pool (Swap_failure { source = source_peer_id }) ;
-      lwt_log_error "Swap to %a failed: %a"
+      match err with
-        Point.pp new_point pp_print_error err
+      | [ Lwt_utils.Timeout ] ->
+          lwt_debug "Swap to %a was interupted: %a"
+            Point.pp new_point pp_print_error err
+      | _ ->
+          lwt_log_error "Swap to %a failed: %a"
+            Point.pp new_point pp_print_error err
     end
 
 let accept pool fd point =

src/utils/lwt_utils.ml

@@ -472,6 +472,16 @@ let protect ?on_error ?canceler t =
 
 type error += Timeout
 
+let () =
+  Error_monad.register_error_kind
+    `Temporary
+    ~id:"utils.Timeout"
+    ~title:"Timeout"
+    ~description:"Timeout"
+    Data_encoding.unit
+    (function Timeout -> Some () | _ -> None)
+    (fun () -> Timeout)
+
 let with_timeout ?(canceler = Canceler.create ()) timeout f =
   let t = Lwt_unix.sleep timeout in
   Lwt.choose [